Curiosity CHAPTER 1 The Wonderful World of Science

Activity 1: Let Us Think and Write

1. Write about a similar problem that you tried to solve.

Schoolvally Answer:

Example Problem: My phone was not charging properly.

2. What steps did you take?

Schoolvally Answer:

I will take the following steps.

1. **Observation:** Noticed the phone wouldn’t charge when plugged in.

2. **Hypothesis:** Thought the charging cable might be faulty.

3. **Experimentation:** Tried using a different charging cable and charger.

4. **Analysis:** The phone charged properly with the new cable, so the problem was with the old cable.

5. **Conclusion:** Replaced the faulty charging cable to fix the issue.

Activity 2: Let Us Think and Write

1. Describe a daily life situation where you feel someone was following a scientific method.

Schoolvally Answer:  A car mechanic diagnosing a problem is using the scientific method. They observe the issue, hypothesize that it might be a faulty part, test by checking and replacing components, and analyze the results to confirm if the problem is resolved.

Activity 3: Let Us Think and Write

1. If you have to ask “Why?” about something, what would you ask about?

Schoolvally Answer:

Schoolvally Answer: Example Question could be:- Why do birds migrate?

2. Try to write down how you would attempt to find an answer to your question.

Schoolvally Answer:

I will try to find the answer using scientific approach as under-

1. Observation: Notice that birds fly long distances at certain times of the year.

2. Research: Look up information about bird migration in books or online resources.

3. Consult Experts: Ask a biologist or ornithologist for insights.

4. Experimentation: Observe bird migration patterns in different seasons or regions.

5. Analysis: Understand that birds migrate to find better food sources and suitable breeding conditions.

1.What is Science?  (Page 1) 

Schoolvally Answer:  

In simple words, we can say that science is a way of thinking, observing and doing things to understand the world we live in and to uncover the secrets of the universe.

2.What will we explore with the help of this book? (Page 3)
Schoolvally Answer:
With the help of this book, we will explore and understand the beautiful world we live in our surroundings and the reasons why changes occur in nature. 

 we will explore how science helps us understand the world, from the variety of life on Earth to the properties of everyday materials. 

 We will investigate food sources, study water’s properties, and learn about the scientific method. 

 The book encourages curiosity and discovery, teaching us how to ask questions and find answers through observation and experimentation. 

3.How can we try toy find answers to our questions on our own? (Page 5) 

Schoolvally Answer:

 We can find answers on our own by using scientific approach.

To find answers to our questions on our own, we can follow these steps:

1. Observe: Notice something interesting or puzzling.
2. Question: Ask a question about what you’ve observed.
3. Hypothesize: Make a guess or prediction about the answer.
4. Experiment: Test your guess through experiments or further observations.
5. Analyze: Review the results to see if they answer your question.
6. Conclude: Draw conclusions based on your findings.

This process helps us systematically explore and understand various phenomena.

4. After all, to be a wise person, you must be a “whys” person! (Page )

Schoolvally Answer:

To be wise, you need to ask "Why?" This curiosity drives learning and understanding, helping you explore and solve problems effectively.

 1. Here are two types of seeds. What differences do you find among the roots and leaf venation of their plants? 

(a) Wheat (b) Kidney beans

Schoolvally Answer:

In wheat we find fibrous roots and parallel venation  in its leaves.  

In kidney beans we find Tap root and reticular venation in its leaves. 

2. Names of some animals are given below. Group them based on their habitats. 

Write the names of aquatic animals in the area marked ‘A’ and 

terrestrial animals in the area marked  ‘B’. 

Enter the names of animals living in both habitats in  part ‘C’. 

Horse, Dolphin, Frog, Sheep, Crocodile, Squirrel, Whale,  Earthworm, Pigeon, Tortoise 

Schoolvally Answer:

(a) aquatic animals ‘A’: Dolphin, Whale.

(b) terrestrial animals ‘B’: Horse, Sheep, Squirrel,  Earthworm.

(c)  living in both ‘C’:  Frog. Crocodile, Tortoise.

3. Manu’s mother maintains a kitchen garden. One day, she  was digging out radish from the soil. She told Manu that  radish is a kind of root. Examine a radish and write what  type of root it is. What type of venation would you observe  in the leaves of radish plant? 

Schoolvally answer:

Radish is a Tap Root with reticular venation.

4. Look at the image of a mountain goat and a goat found in the  plains. Point out the similarities and differences between  them. What are the reasons for these differences?

Schoolvally Answer:

Similarities:

(a) small hooves that helps them to run faster.

(b) Horns to protect them selves.

Differences: 

(a) Mountain goats have thick fur to keep them warm.

(b) Mountain goats have more fat deposit to survive in winter.

 5. Group the following animals into two groups based on  any feature other than those discussed in the chapter— cow, cockroach, pigeon, bat, tortoise, whale, fish,  grasshopper, lizard. 

Schoolvally Answer:

Another way to group these animals is by their mode of reproduction:

1. Lay eggs:

   - Cockroach

   - Pigeon

   - Tortoise

   - Fish

   - Grasshopper

   - Lizard

2. Give birth to young ones:

   - Cow

   - Bat

   - Whale

Alternately we see that their is is difference in their skin types like 

• Feathered: Pigeon
• Scaly: Fish, Lizard, Grasshopper
• Furry hair: Cow, Bat, Whale
• Exoskeleton: Cockroach

Also by way of food thy eat: 

• Herbivores: Cow, Tortoise
• Carnivores: Lizard, Bat (mostly)
• Omnivores: Pigeon, Whale
• Insectivores: Cockroach, Grasshopper

In this grouping, animals that lay eggs are in one group, while those that give birth to live young are in the other.

6. As the population grows and people want more comfortable  lives, forests are being cut down to meet various needs.  How can this affect our surroundings? How do you think  we can address this challenge? 

Schoolvally Answer:

As forests are cut down to make way for growing populations and their needs, it leads to habitat loss, reduced biodiversity, and increased carbon emissions, which can contribute to climate change. 

To address this challenge, we can focus on sustainable practices like reforestation, using resources more efficiently, and supporting conservation efforts to protect existing forests.

7. Analyse the flowchart. What can be examples of ‘A’ and ‘B’?

Schoolvally answer:

'A'  could be carrot or radish.

'B' could be grass or banana.

 8. Raj argues with his friend Sanjay that “Gudhal (hibiscus)  plant is a shrub”. What questions can Sanjay ask for  clarification? 

Schoolvally answer:

Questions that qualifies shrubs like

(a) Does it has soft stem or hard stem.

Shrubs have hard stem

(b) Can it be grown in pot?

(Shrubs grow big and need to be planted in ground.)

 9. Based on the information in the table, find out examples of  these plants for each group. 

 Group - Type of seed - Type of root -  Examples 

Schoolvally answer:

A) Dicot - Taproot - Chikpick

B) Monocot - Fibrous roots - Maize

 (a) What other similarity do plants of group A have? 

They have  Reticulate venation.

(b) What other similarity do plants of group B have? 

They have parallel venation in their leaves.

 10. Observe the labelled part of a duck in the picture given  below. What differences do you observe in the feet of the  duck compared to the other birds? Which activity would the  duck be able to perform using this part? 

(a) Duck (b) Pigeon 

Schoolvally answer:

We can see the feet of the duck are webbed, this adaptation will help duck to swim faster in water.

 Read about one Indian scientist or a wildlife biologist  who is working towards protection of India’s biodiversity.  Prepare a brief report. 

Schoolvally Answer:

 Director Wildlife Institute of India 

Shri Virendra R. Tiwari,  currently ( 2024) Director Wildlife Institute of India a seasoned Indian Forest Service officer and Chemical Engineer, is the Director of the Wildlife Institute of India. With over three decades of experience, he has held key roles including Field Director at Tadoba-Andhari Tiger Reserve and Additional Principal Chief Conservator of Forests for the Mangrove Cell. He has played a crucial role in wildlife conservation, including the creation of protected areas and mangrove preservation. His leadership is set to advance wildlife conservation efforts in India.

 Explore the contributions of Divya Mudappa, Usha Lachunga,  Ghazala Shahabuddin, Nandini Velho, Vidya Athreya, Uma  Ramakrishnan and Divya Karnad towards biodiversity in  India. Prepare a report of the work done by any three of them 

Schoolvally Answer

1. Divya Mudappa:

Divya Mudappa's research focuses on the Western Ghats, a biodiversity hotspot in India. She studies the ecological impacts of land use changes and human-wildlife conflicts. Mudappa works on conservation strategies that involve local communities, helping to mitigate conflicts and promote sustainable practices to protect key species and habitats in the Western Ghats.

2. Vidya Athreya:

Vidya Athreya is known for her work on reducing human-wildlife conflicts, particularly with leopards in India. She develops and implements strategies to minimize conflicts between leopards and human populations, such as community education and innovative deterrent methods. Her research aims to ensure safe coexistence and improve the conservation status of leopards.

3. Uma Ramakrishnan:

Uma Ramakrishnan focuses on the genetic conservation of wildlife species, including tigers and other large carnivores. Her work involves studying the genetic diversity and population dynamics of these species to inform conservation strategies. Ramakrishnan’s research helps in understanding the genetic health of populations, which is critical for their long-term survival and effective management.

4. Usha Lachunga:

Usha Lachunga works on the conservation of the biodiversity in the northeastern states of India. Her efforts include researching the impacts of forest management practices on local flora and fauna and advocating for sustainable development in these ecologically sensitive regions.

5. Ghazala Shahabuddin: 

Ghazala Shahabuddin focuses on the conservation of grasslands and their ecosystems. Her research examines the effects of land use changes and policy on biodiversity. She also works on integrating ecological research with conservation strategies to protect grassland habitats and species.

These scientists contribute significantly to biodiversity conservation in India through their focused research and innovative solutions to address various ecological challenges.

6. Nandini Velho: Nandini Velho’s research is centered on the conservation of the Eastern Ghats and its wildlife. She focuses on understanding the ecological needs of various species and promoting conservation strategies that address habitat loss and fragmentation. Her work includes engaging with local communities to support conservation efforts. 

 Find out about ‘Project Tiger’ and other similar projects  initiated in India to protect our biodiversity. Prepare a  presentation for your class. 

Schoolvally Answer:

Project Tiger, launched in India in 1973, aims to protect tigers and their habitats by establishing reserves and combating poaching. The initiative has led to the creation of over 50 tiger reserves and a notable increase in tiger populations. Despite these successes, challenges like habitat fragmentation and human-wildlife conflict continue, requiring ongoing conservation efforts and community involvement.

EQ 1. Define Biodiversity?

Schoolvally Answer:

 The variety of plants and animals found in a particular  region contributes to the biodiversity of that region.  

 Each member in the biodiversity of a region has a different  role to play. For example, trees provide food and shelter to  some birds and other animals, animals help in spreading  seeds after eating fruits, and so on. 

EQ 2.  What is the importance of grouping? 

Schoolvally Answer:

 Grouping s the process that makes it  easier to understand and study plants and animals around us.

The  basis of grouping is the similarities and differences they exhibit.  

This grouping helps was to understand them better.  For example, grouping of plants based on height and nature of stem. Tall plants, medium plants, short plants. 

EQ 3. What differences do you observe  among herbs, shrubs, and trees? 

Schoolvally Answer:  

The main difference between herbs, shrubs and trees is that:

Herbs have soft, non-lignified, unbranched stems. eg:  For example, a tomato plant is a  herb, Mint is herb. 

Shrubs have woody, immediately branched, multi stems. eg: a rose plant is a shrub. Tulsi is an aromatic shrub (Note it has medicinal properties of herbs but it is not of group herb.)It belongs to the basil family.  

Trees have woody stems that grow upright for about a meter before branching. eg: Mango is Tall tree, Apple trees are generally small trees.

EQ 4. Define Climbers and Creepers?

Schoolvally Answer:

 The plants with weak stems which needs support to climb and  grow, they can not stand upright on their own are are called climbers. 

 Some plants creep along the  ground means that they grow horizontal to ground and are called creepers. 

EQ 5. What is the similarities and difference between climbers and creepers? 

Schoolvally answer:

 The climbers and creepers both are weak-stemmed plants and, as a result, fail to grow erect in the absence of any support. 

The main difference between them is that creepers grow along with the soil horizontally their stems run parallel to ground, while climbers can grow vertically holding any vertical surface with their special organ called 

tendrils. 

EQ 6. Define Venation and its types?

Schoolvally Answer:

Thin lines on the leaves of the plants  are called veins. The pattern of veins on the leaf  is called venation. The arrangement of veins in a leaf is called the venation or venation pattern.  parallel venation

When the veins run in straight lines across the length of the leaf without converging or touching or intersecting at a point this pattern is called Parallel venation. 

For example, the leaves of banana plants and grasses exhibit parallel venation.

When the veins form a net like pattern or  web of veins on both sides of a thick middle vein. This pattern is  called reticulate venation.

  For example, leaves of hibiscus  exhibit reticulate venation 

EQ 7. Types of root system in plants?

Schoolvally Answer: 

There are two main types of root system as given below:

Taproot: Consists of a single, main root that grows vertically downward. 

A tap root system has a single main root that grows down.

Examples include carrots and radishes. hibiscus. 

 A fibrous root system forms a dense network of roots that spreads out near the soil surface. Roots of appear as a bunch of similar-sized thin roots arising from the base  of the stem.

Examples include, Grasses, wheat, rice corn.

EQ  8. Is there any relation between type of venation and root system? Give example.

Schoolvally Answer:  Yes, Plants with  reticulate venation have taproots, while those with parallel  venation have fibrous roots.  

Example- 

(a)Chickpea (chana) is example of a plant with  taproots and reticulate venation in leaves. 

(b)Wheat is an example of a plant with fibrous roots and parallel venation  in its leaves. 

EQ 9.  Is there any relation among the seed of a plant, types of  root and leaf venation? 

Schoolvally answer:

 Plants that  have seeds with two cotyledons (thick leaf like structure) are called dicotyledons.

 Dicot plants have reticulate venation and tap roor system. 

eg: chickpea has a two cotyledon.

Plants seeds with single thin cotyledon are called monocotyledons (monocots).

 monocot plants have parallel venation and a fibrous  root system. 

eg: Maize has a single thin cotyledon.

EQ 10. Define Adaptation? 

Schoolvally Answer:

 The special features that enable plants  and animals to survive in a particular region are called  adaptations.

(a) The shape of the deodar tree is its adaptation.

(b) The short height and  smaller leaves to  survive through the heavy winds  on mountain tops.  is its adaptation.

(c) The stream lines body of fishes is adaptation it helps them to move faster.

(d)  Camels store food in their big hump and water in long neck. this is result of adaptation.

EQ 11. Define habitat and its components? 

Schoolvally Answer:

A habitat is a living or dwelling place of a organism where they can breed and reproduce freely.

In other words  A habitat is a place where an organism makes its home. A habitat meets all the environmental conditions an organism needs to survive. For an animal, that means everything it needs to find and gather food, select a mate, and successfully reproduce.

Hence we can say that, the surroundings where plants and animals live naturally, is called their habitat. Several kinds of plants and animals may share the same habitat.

The living organisms (both plant and animas) living in a habitat are called its biotic factors.

The various non-living things such as rocks, soil, air, sunlight and water in a habitat are its abiotic components. 

EQ 12. What are the different ways you can group plants and  animals based on their habitats? 

Schoolvally answer:

 One way is to group them into those 

(a) ‘that live on land’

(b) those ‘that live in water’ and

(c) those who 'live on both'.

 The plants and animals that live on land are said to live in terrestrial habitats and are called terrestrial animals. 

For examples of terrestrial habitats  are forests, deserts, grasslands, and mountains. Cow, ant, snake and sparrow are terrestrial animals. 

 The plants and animals that live in water are said to live  in aquatic habitats and are known as aquatic animals. 

Ponds, lakes, rivers, and oceans are aquatic habitats. Fishes, water llily, Lotus, octopus are aquatic animals 

Some animals, such as frogs, can live in water as well as  on land. These are called amphibians. They share both the habitats.

EQ 13. Explain 'sacred grooves' ?

Schoolvally Answer:

 Sacred groves are undisturbed patches of forests. Their sizes  may vary from quite small to very large. Sacred groves are  found all over India. They are home to different kinds of  plants and animals, including  numerous medicinal plants.   These are protected by the  local community and no one is  allowed to harm any animals  and cut trees in these groves,  or disturb the area. 

Thus, sacred groves are  a community protected  treasure of biodiversity.

EQ 14. Possible reason for loss of bio diversity?

Schoolvally Answer:

The reason is the damage of habitats of  plants and animals. They lose  their homes, food and other resources resulting in the loss  of biodiversity.

 We must protect biodiversity to ensure that our planet is full  of life, helping plants and animals to survive and thrIve. 

 1. Pick the odd one out and give reasons:   

(i) Jowar, Bajra, Ragi, Chana  

(ii) Kidney beans, Green gram, Soya bean, Rice 

Schoolvally Answer:

(i) Chana is a legume or pulsed and mot millet.

(ii) Rice is a cereals not pulses.

2. Discuss traditional versus modern culinary practices in  India.  

Schoolvally Answer:

 Choice of food may vary according to the cultivation of food  crops in a region, taste preferences, culture and traditions,  and so on.

 Cooking practices, also called culinary practices, have  changed over time. There is a significant difference between  traditional and modern culinary practices.   

 Culinary practices have changed over time. There is a  significant difference between traditional and modern  methods of cooking food. 

(a) Earlier, most  cooking was done using a chulha . Nowadays, most  of us cook using a modern LPG gas stove . 

(b) Earlier, most  grinding was done manually using a sil-batta. These days, we use an electrical grinder for ease of grinding. 

 These changes may be due to factors such as  technological development, improved transportation and  better communication. 

3. A teacher says that good food may act as medicine. Ravi is  curious about this statement and has some questions for his  teacher. List at least two questions that he can ask.

Schoolvally Answer:

Ist question he can ask is can it improve my brain power?

Second question he can ask is can it cure my eye sight?

Third. Can it make me taller?

Forth, Can it make my dry skin soft?

Fifth, Can  it cure my bad breadth? etc

 4. Not all delicious foods are necessarily healthy, while not all  nutritious foods are always enjoyable. Share your thoughts  along with a few examples. 

Schoolvally Answer:

So true, Bitter guard (kerala) is not tasty to eat but it can  lower bad cholesterol levels, reducing the risk of heart disease,

'Amla' is so sour, but it can help to increase immunity against common cold amd minnor ailments. 

We find so many tasty foods on the food carts and restaurant like burger and pizza they are high In fats and cause obesty.

'Golgappy' are tangy but can cause gastric ailments and high BP due to excessive salts  and spices in them.

We should eat to stay fit and not to enjoy it , cause of its taste and colour. We should eat balanced diet and exercise to say healthy.

 5. Medu does not eat vegetables but enjoys biscuits, noodles and white bread. He often has stomach ache and constipation.  What changes should he make in his diet to get rid of these  problems? Explain your answer.

Schoolvally Answer:

To get rid of these problems he should eat dietary fibre also called as roughage.   

They help our body get rid of  undigested food and ensure smooth passage of stools. green leafy vegetables and fruits are good source of it.

(b) He should drink lot of water.

(c) He should reduce fats, oils and ghee from this diet.

 6. Reshma had trouble seeing things in dim light. The doctor  tested her eyesight and prescribed a particular vitamin  supplement. He also advised her to include a few food items  in her diet.  

(i) Which deficiency disease is she suffering from?

Schoolvally Answer:

 Loss of  vision. 

 (ii) Which food component may be lacking in her diet? 

Schoolvally Answer:

Vitamin A

(iii) Suggest some food items that she should include in  her diet to overcome this problem (any four). 

Schoolvally Answer:

 Papaya, carrot,  mango, milk. 

7. You are provided the following:  

(i) Canned fruit juice  

(ii) Fresh fruit juice  

(iii) Fresh fruit 

Which one would you prefer and why? 

Schoolvally Answer:

I will prefer fresh fruits, because we know that cutting and peeling  may  also result in the loss of some vitamins. Also eating fresh fruits will give me dietary fiber which is important for expulsion of water products from body. 

 8. Gourav got a fracture in his leg. His doctor aligned the bones  and put on a plaster. The doctor also gave him calcium tablets.  On the second visit, the doctor gave him Vitamin D syrup  along with calcium tablets. Refer to Fig. 3.5 and answer the  following questions:  

(i) Why did the doctor give calcium tablets to Gourav?

Schoolvally Answer:  

Doctor gave calcium tablets to Gaurav as our bones are made up of calcium, Added calcium will help in joining of bones.

(ii) On the second visit, why did the doctor give Vitamin D syrup along with calcium tablets? 

Because, Vitamin D Helps body absorb  calcium for bone. 

(iii) What question arises in your mind about the choices  made by the doctor in giving the medicines?  

Schoolvally Answer:

Why did the doctor not give him Vitamin D syrup ist time?

 9. Sugar is an example of carbohydrates. Sugar is tested with  iodine solution but it does not change to blue-black colour.  What can be a possible reason?  

Schoolvally Answer:

Yes, sugar is a example of carbohydrates but it is not starch another type of carbohydrate. The iodine test is for starch and not sugar so it did not turn iodine solution to blue-black colour.

10. What do you think of Raman’s statement, “All starches are  carbohydrates but not all carbohydrates are starches.’’  Describe the design of an activity to test your answer. 

Schoolvally Answer:

 Carbohydrates are a broad category of organic compounds that include sugars, starches, and fiber. 

We can test this with the help of simple activity. We can add few drops on iodine solution on sugar, starchy potato and mango. We will see that only colour of potato changes , Hence we can say that all carbohydrates are not starches.  

11. While using iodine in the laboratory, a few drops of iodine  fell on Mishti’s socks and a few fell on her teacher’s saree.  The drops of iodine on the saree turned blue-black while the  colour on the socks did not change. What can be a possible  reason? 

Schoolvally Answer:

 Mishti’s Socks: The absence of color change suggests that the socks do not contain starch. The fabric of the socks might be made of materials like cotton, polyester, or nylon these fibers do not react with iodine in the same way as starch does.

Teacher’s Saree: If the saree changed color to blue-black, it indicates that the fabric contains starch or a starch-like substance. Starch is commonly used in the finishing of fabrics to give them a crisp texture. 

Therefore, the possible reason is that the saree may have been treated with starch or might have had starch residues.

12. Why are millets considered a healthy choice of food? 

 Schoolvally Answer:

They have regained  popularity due to their numerous health benefits. They are  good sources of vitamins, minerals like iron and calcium,  and dietary fibres as well. 

That is the reason they are  also called nutri-cereals. They contribute significantly to  a balanced diet required for the normal functioning of  our body. 

Can  eating just millets suffice for the nutritional requirements  of the body? Discuss. 

Schoolvally Answer:

No, Just eating millets will not suffice because that lack fats and some other vitamins and minerals. 

13. You are given a sample of a solution. How would you check  the possibility of it being an iodine solution? 

Schoolvally Answer:

 We know that the iodine solution changes colour of starch to blue back.   We will add few drops of this solution on grinded potato in a test tube, if the potato color changed, indicates the solution to be iodine. 

T he Apatani tribe of Arunachal Pradesh produces a salt  called tapyo to fulfil their dietary requirements. Collect  more information from the internet about their salt making  process and the need to make their own salt. Collect pictures  and paste them on a chart paper. Also, write a paragraph  about the process of making this salt and its usefulness. 

Schoolvally Answer:

 The Apatani community takes pride in their century old indigenous knowledge of 

making salt. The salt is called 'Tapyo' derived from the extracts of a wild grass that grows in the forest. They collect and process the grass to make the Tapyo which is then consumed with food and drinks. 

 Vegetables or fruits that grow naturally in the forest or  nearby fields without being cultivated by farmers are  considered wild varieties. Traditionally, many tribal groups  in India depend on these wild varieties, which form a part  of their food. Read about ranbhajis from Maharashtra and  edible mushrooms from Himachal Pradesh. Are you aware  of any such wild varieties of food from your region? Discuss  in class 

Schoolvally Answer

Yes, in my region we eat a type of fern called locally as 'casroad' they grow on their own in forest and is harvested by locals and sold.

List junk foods you eat frequently. Ask your friends also to  make such lists. On the basis of these lists, write a letter to  your principal requesting to ban certain junk foods inside  the school campus. Suggest some healthy options 

Schoolvally Answer:

Just foods that we eat frequently,  Samosas, Magi, Biscuit, Pastry, Burger , pizza.

To

The Principal,

School VALLY,

West Virginia.

Sub: "To ban sale of junk food in canteen."

Sir,

I am a student of class sixth 'A' in your school, every day one or the other class mate of mine is complaining stomach ache and  also the teachers are complaining that we have become very lazy and also obese.

Sir, now a days students of all the classes are buying and eating food available in canteen. Some times they eat their lunch and then eat the packed snakes or fried food in the canteen and drink cola drinks containing high sugar and caffeine.

This is making them mentally week , obese and  they often fall ill. The list of absentees due to illness has also increased.

So, I request you to stop the sale of packed and junk food in the canteen and replace it with fruit patters and wholesome diet like 'rajma chawal' and roti sabzi. We can have packed Lassi or flavor milk to drink .

Thanking-You

Yours obediently,

Nick Jr. Smith

Health Monitor.

 Find out the variation in nutritional requirements of  different individuals based on age, physical activity and  health conditions. Record your observations. Discuss and  analyse. 

Schoolvally Answer:

Based on Age:

 Children and teenagers need higher amounts of calories, protein, and calcium for growth and development. Adults have more stable needs but may require fewer calories. Older adults often need more calcium, vitamin D, and fiber to maintain bone health and digestive function. 

Based on physical activity:

 Active individuals like sports person require more calories and protein to support muscle growth and energy requirement. Sedentary or sitting  individuals have lower calorie needs but every one needs balanced nutrients.

Based on health conditions:

 People with conditions like diabetes need to manage their carbohydrate intake, while those with heart disease may need lower fats, ghee and salt. Individuals with digestive problem might require easily digestible foods etc.

 Prepare a diet chart to provide a balanced diet to a  twelve-year-old child. The diet chart should include food  items that are not expensive and are commonly available  in your area 

Schoolvally Answer: 

Balanced Diet Chart for a 12-Year-Old

Breakfast:

• Boilled eggs with milk and a banana
• Brown Bread

Lunch:

• Whole wheat chapati or rice
• Lentil dal (dal) or vegetable curry
• A serving of mixed salad (cucumber, tomato, carrot)

Afternoon Snack:

• Yogurt with a spoonful of honey or a small serving of fruit and nuts.

Dinner:

• Grilled or steamed chicken/fish or a serving of chickpeas
• Brown rice or whole wheat chapati or rice.

Hydration:

• Water throughout the day
• Herbal tea or fresh fruit juice (without added sugar and preservatives)
• And a glass of milk in the night before going to bed.

This chart offers a mix of carbohydrates, proteins, vitamins, and minerals, using affordable and readily available foods.

EQ 1. Why do you think a marathon  runner drinks glucose water during and after a race? 

Schoolvally answer:

Glucose is an example of  a carbohydrate. Glucose provides instant  energy.  So players and runners drink glucose to recover energy loss.

EQ 2. Define energy giving foods?

Schoolvally Answer:

 Carbohydrates and fats provide us energy for performing various activities. Therefore, they are called energy-giving  foods.

EQ 3. What are body-building foods? 

 Schoolvally Answer:

 Protein-rich foods help in growth and repair of our body. These are, therefore, called  body-building foods. 

 Proteins are also an important part of our food.  Milk products and pulses are good sources of protein.  Sportspersons need proteins in larger quantities to build their  muscles. 

 The right amount of protein must be included in the diet of  growing children for their proper growth and development.    

Plant source of proteins are:  pulses, beans,  peas and nuts 

Animal source of proteins are:  milk,  paneer, egg, fish and meat. 

EQ 4. What are protective  nutrients?

Schoolvally answer:

 Vitamins and minerals are also called protective  nutrients. These nutrients protect our body from diseases and  keep us healthy. 

EQ 5. Why should we eat raw fruits?

Schoolvally Answer:

 Some nutrients like vitamin C and  others are lost during cooking due to high heat.  It Would be wise to include fruits and uncooked vegetables into  our diet.

 Excessive washing, cut or peeled vegetables and fruits may  also result in the loss of some vitamins. 

EQ 6. Roughage don't provide any energy should we eat them?

Schoolvally Answer:

 In addition to the essential nutrients, our body needs dietary  fibres and water. Dietary fibres, also known as roughage, They do  not provide any nutrients to our body, but they are an  essential component of our food. They help our body get rid of undigested food and ensure smooth passage of stools. Roughage  in our food is provided mainly by suitable plant products.  

 Green leafy vegetables,  fresh fruits, wholegrains,  pulses and nuts are good  sources of roughage. 

EQ 7. What are different types of nutrients and their uses?

Schoolvally Answer:

 Food components that provide energy, support growth,  help repair and protect our body from diseases, and maintain  various bodily functions are called nutrients 

In other words, nutrients are substances in food that help our bodies grow, stay healthy, and get energy. There are six main types:

1. Carbohydrates: Carbohydrates are one of the primary sources  of energy in our diet. Provide energy (like sugars and starches).
2. Proteins:  Proteins are also an important part of our food.  Milk products and pulses are good sources of protein. Help build and repair tissues (found in meat, beans, and nuts).
3. Fats: Fat is a source of  stored energy. nuts, and seeds. Ghee and  various kinds of oils are grouped  under category, which is called fat . Fats give long-lasting energy and help absorb vitamins (like those in oils and butter).
4. Vitamins: Support various body functions.  vitamins (A, B1 , C  and D) protect our body from  various diseases.
5. Minerals: Help with processes like bone building (such as calcium and iron) and also makes us strong.
6. Water: Keeps us hydrated and helps with all body functions.  It helps the  body absorb nutrients from  food. It removes waste from  the body through sweat  and urine. 
7.  Dietary fibre: Roughage is normally referred to as dietary fibre. It is the indigestible portion of food that is obtained from plants. They do not give any nutrients to our body but play an important part of a healthy diet plan.

EQ 8. Define  deficiency diseases or disorders ? Give Eg.

Schoolvally Answer: 

Deficiency of one or more nutrients in our diet for a long  time can lead to deficiency diseases and disorders.  vitamins (A, B1 , C  and D) and minerals (calcium, iodine, and iron) are two  groups of food components that protect our body from  various diseases. Below is the list of deficiency diseases:

Food Component-  Vitamin A 

 Functions- Keeps eyes  and skin  healthy. 

Sources- Papaya, carrot,  mango, milk 

 Deficiency  disease/ disorder- Loss of  vision Poor vision,  loss of vision  in darkness  (night  blindness),  sometimes  complete loss  of vision.

 Symptoms-   Poor vision,  loss of vision  in darkness  (night  blindness),  sometimes  complete loss  of vision. 

 Food Component-  Vitamin B1 

 Functions-  Keeps heart  healthy and  supports  body to  perform  various  functions .

 Sources-  Legumes, nuts,  whole grains,  seeds, milk  products  

 Deficiency  disease/ disorder-  Beriberi 

 Symptoms-  Swelling,  tingling or  burning  sensation  in feet and  hands,  trouble in  breathing.  

 Food Component-  Vitamin C 

 Functions-  Helps body  to fight  diseases. 

 Sources-  Amla, guava,  green chilli,  orange, lemon .

 Deficiency  disease/ disorder-  Scurvy . 

 Symptoms-  Bleeding  gums, slow  healing of  wounds.  

 Food Component-  Vitamin D

 Functions-  Helps body  absorb  calcium for  bone and  teeth health 

 Sources-  Exposure to  sunlight, milk,  butter, fish,  eggs 

 Deficiency  disease/ disorder-  Rickets  

 Symptoms-  Soft and bent  bones  

 Food Component-  Calcium 

 Functions-  Keeps  bones  and teeth  healthy. 

 Sources-   Milk/soya milk,  curd, cheese,  paneer. 

 Deficiency  disease/ disorder-  Bone and  tooth  decay 

 Symptoms-  Weak bones,  tooth decay. 

 Food Component-  Iodine 

 Sources-  Helps to  perform  physical  and mental  activities 

 Functions-  Seaweed,  water chestnut  (singhada),  iodised salt.

 Deficiency  disease/ disorder-  Goitre 

 Symptoms-  Swelling at  the front of  the neck. 

 Food Component-  Iron 

 Functions-   Important  component  of blood. 

 Sources-  Green leafy  vegetables,  beetroot,  pomegranate .

 Deficiency  disease/ disorder-   Anaemia. 

 Symptoms-  Weakness,  shortness of  breath. 

EQ 9. How can we show the presence of Fat in food item?

Schoolvally Answer:

 To test for fats, place small food samples on separate pieces of paper and press them. An oily patch on the paper indicates the presence of fats. 

EQ 10. How can we show the presence of starch in food item?

Schoolvally Answer:

 For starch or carbohydrates, grind food items into a paste, add a few drops of iodine solution, and check for a blue-black color, which shows the presence of starch. 

EQ 11. How can we show the presence of starch in food item?

Schoolvally Answer:

To test for proteins, grind food items into a paste, take half spoon in each test tube and  Add 2–3 teaspoons of water to each test tube and shake  them well.

 Add two drops of copper sulphate solution to each test  tube using a dropper.

 Now, take another dropper and add 10 drops of caustic  soda solution to each tube.

 Shake well and leave the test tubes undisturbed for a  few minutes. A violet color indicates the presence of proteins.

EQ 12. Define Balanced Diet? 

Schoolvally Answer:

 A diet that has all essential nutrients, roughage, and water  in the right amount for proper growth and development of  the body is known as a balanced diet.

EQ 13. What are millets, why are thay called nutri-cereals? 

Schoolvally Answer:

 Millets are small-sized grains and have been an integral  part of the Indian diet for centuries. 

 jowar, bajra, ragi,  and sanwa  are some of the examples.

They have numerous health benefits. They are  good sources of vitamins, minerals like iron and calcium,  and dietary fibres as well. 

 They can be easily cultivated in different climatic  conditions 

That is the reason they are  also called nutri-cereals. 

EQ 14. What is food mile? Why is it 

important to reduce it?

Schoolvally Answer:

 The entire distance travelled by a bag of wheat or any  other food item, from the producer to the consumer, is  known as its food miles. 

Reducing food miles is important  because it helps to cut down the cost and pollution during  its transport. Secondly, it's helps support local farmers.

Third, It also  keeps our food fresher and healthier for consumption.  

EQ 15.Why should we not waste fooe?

Schoolvally Answer:

We should not waste food and remember the time and effort put by our  farmers and other community members in  getting the food from the farm to our plate. 

 Also we should be thankful to the God for being fortunate to get food. Lacks of people die every year in our country because of hunger. 

EQ 16. Define Junk food is good for us or bad?

Schoolvally Answer:

Food that is high in calories but low in nutritional content is called Junk Food.

 Junk foods are unhealthy as they contain high levels of sugar  and fats but little protein, minerals, vitamins, and dietary  fibres. 

1. Fill in the blanks  

Schoolvally Answer:

(i) Unlike poles of two magnets    .      Attract      .        each other,  whereas like poles  .     .      Repel     .     each other.  

(ii) The materials that are attracted towards a magnet are called    .       Magnetic Material   . 

(iii) The needle of a magnetic compass rests along the        North - South     direction. 

(iv) A magnet always has  .   two     poles.

 2. State whether the following statements are True (T) or  False (F).  

(i) A magnet can be broken into pieces to obtain a single pole. [ False ]  (ii) Similar poles of a magnet repel each other. [ True ]  

(iii) Iron filings mostly stick in the middle of a bar  magnet when it is brought near them. [ False ]  

(iv) A freely suspended bar magnet always aligns with the north-south direction. 

[ True ]

 3. Column I shows different positions in which one pole of a  magnet is placed near that of the other. Column II indicates  the resulting interaction between them for different  situations. Fill in the blanks.

 Column I Column II 

 N - N   ------

 N  -       –-----     Attraction 

 S – N     ------    

    -  S    ---------   Repulsion 

Schoolvally Answer:

 N  -  N   --------    Repulsion

 N  -   S    –-----     Attraction 

 S   –  N     ------    Attraction

 S   -  S    ---------   Repulsion 

 4.  Atharv performed an experiment in  which he took a bar magnet and rolled it over a heap of steel U-clips  (Fig. 4.15).  According to you, which of the options given in Table 4.3 is likely  to be his observation? 

 Position A Position B Position C 

(i) 10 2 10 

(ii) 10 10 2 

(iii) 2 10 10 

(iv) 10 10 1 

Schoolvally Answer:

 (i) 10 2 10 ,  because the intensity of magnetic attraction is stronger near the poles. 

 5. Reshma bought three identical metal bars from the market.  Out of these bars, two were magnets and one was just a  piece of iron. How will she identify which two amongst the  three could be magnets (without using any other material)? 

Schoolvally Answer:

Bar that attracts both the ends of other bars is Iron as it has not shown any magnetic properties.

6. You are given a magnet which does not have the poles  marked. How can you find its poles with the help of another  magnet which has its poles marked? 

Schoolvally answer:

Yes, this is possible. We know that the like poles of a magnet repel each other and vice versa.

 Place the magnet  with marking of north pole and south pole, near  this magnet under observation .If it repels mark this pole as North pole if it attracts mark it as south pole.

 7. A bar magnet has no markings to indicate its poles. How would  you find out near which end its North pole is located without  using another magnet? 

Schoolvally answer:

Freely suspend the magnet and let it stabilize ,  The end of the magnet that points towards the geographic North is the magnet’s North pole. And, the end pointing towards the geographic South is the magnet’s South pole 

8. If the earth is itself a magnet, can you guess the poles of earth’s magnet by looking at the direction of the magnetic compass? 

Schoolvally Answer:

Yes, this is possible the North pole of the magnetic needle  always points to the north pole of the earth. ( north south direction )

9. While a mechanic was repairing a  gadget using a screw driver, the steel  screws kept falling down. Suggest a way  to solve the problem of the mechanic on  the basis of what you have learnt in this  chapter. 

Schoolvally Answer:

The mechanic can temporary magnetize the screw driver. This will keep the screws attracted to the screw driver and stop screw from falling.

10. Two ring magnets X and Y are arranged as shown in Fig. 4.16. It is observed that the  magnet X does not move down further.  What could be the possible reason?  Suggest a way to bring the magnet X in  contact with magnet Y, without pushing  either of the magnets. 

Schoolvally Answer:

 The possible reason is similar polarity.

To let the contact happen we need to flip the magnet, And make unlike poles face each other, so they can attract.

 11. Three magnets are arranged on  a table in the form of the shape  shown in Fig. 4.17. What is the  polarity, N or S, at the ends 1, 2, 3,  4 and 6 of the magnets? Polarity  of one end (5) is given for you. 

Schoolvally Answer:

6 = South Pole

4 = South Pole

3 = North Pole

2 = South Pole

1 = North Pole

Q1. Find out about the Maglev Train and try to make its  model. 

Schoolvally Answer: 

Maglev (Magnetic Levitation) trains use magnetic forces to lift and propel the train along its track without physical contact. This technology eliminates friction, allowing for high-speed, smooth, and quiet travel.

Q2. Try to find out why there is a need to make magnets of  different shapes.

Schoolvally Answer:

 Each magnet’s shape influences how it is used. The shape of a magnet determines how the magnetic field lines are arranged outside of the magnet as well as the strength of its pull.

Accordingly they find their usages in various electronic equiplents like Speakers, Head phones, Magnetic trains, automatic doors etc. 

In medicine field, magnets find their use in following activities:

-  MRI Scanners : To create detailed images of the body's internal structures.

- Magnetic Therapy : To reduce pain and inflammation.

- Magnetic Drug Delivery : To target and deliver medication to specific areas.  

Q1 Define Magnetic materials and Non magnetic material?

Schoolvally Answer:

 The materials which are attracted towards a magnet are called magnetic materials.

 The materials which are  not attracted towards a magnet are called  non-magnetic materials.    

The metal iron is a magnetic material.  Nickel and cobalt are other metals that are  also magnetic.

 The materials which are  not attracted towards a magnet are called  non-magnetic materials.

Q2. What are magnetic poles? How can we find one?

Schoolvally Answer:

 The ends of the magnet are called the  two poles of the magnet—the North pole and  the South pole. 

The North Pole of the magnet always align to the North pole of earth. This property of Magnet is used to identify the pole of magnet.

 If a magnet is broken into smaller pieces, North and South poles always  exist in pairs even in the smallest piece of the magnet.  A single North pole or a South pole cannot exist. 

Q3. A freely suspended  magnet rests along the north-south direction Why? 

Schoolvally Answer:

This is because our earth itself behaves like a giant magnet.

 1. Some lengths are given in Column I of Table 5.5. Some units  are given in Column II. Match the lengths with the units  suitable for measuring those lengths.  

Schoolvally Answer:

 Column I - Column II 

Distance between Delhi and  Lucknow - kilometre 

Thickness of a coin - millimetre 

Length of an eraser - centimetre 

Length of school ground - metre 

 2. Read the following statements and 

mark True (T) or False  (F) against each.  

Schoolvally Answer:

(i) The motion of a car moving on a straight road is an  example of linear motion. [ True ]  

(ii) Any object which is changing its position with respect  to a reference point with time is said to be in motion. [ True ] 

(iii) 1 km = 100 cm [ False ]  

3. Which of the following is not a standard unit of measuring  length? 

(i) millimetre 

(ii) centimetre 

(iii) kilometre 

(iv) handspan

Schoolvally Answer: 

(iv) Handspan 

4. Search for the different scales or measuring tapes at  your home and school. Find out the smallest value that  can be measured using each of these scales. Record your  observations in a tabular form. 

Schoolvally Answer:

The smallest value that can be measured is 1mm.

5. Suppose the distance between your school and home is 1.5 km. Express it in metres. 

Schoolvally Answer:

We know that 1 km = 1000 mts

Therefore:

1.5 km ×1,000 m/km=1,500 m  

 6. Take a tumbler or a bottle. Measure the length of the curved  part of the base of glass or bottle and record it. 

Schoolvally Answer:

Take a think thread and wind it once around the bottle so that the two ends meet.

Step 2. Measure the length of this thread

7. Measure the height of your friend and express it in 

(i) metres  

(ii) centimetres and 

(iii) millimetres. 

Schoolvally Answer:

The height of my friend is 152 Cms

Height in mts:

we know 1 mts = 100 cm

 152 cm÷100 cm/m=1.52 m 

Height in mm.

We know 1 cm is 10 mm.

 152 cm×10 mm/cm=1,520 mm 

8. You are given a coin. Estimate how many coins are required  to be placed one after the other lengthwise, without  leaving any gap between them, to cover the whole length  of the chosen side of a notebook. Verify your estimate by  measuring the same side of the notebook and the size of the  coin using a 15-cm scale. 

Schoolvally Hint:

Spread the coins on the notebook with out over lapping. then measure.

9. Give two examples each for linear, circular and oscillatory  motion. 

Schoolvally Answer:

Linear motion:

1. A car moving on straight road.

2. An airplane landing.

Circular motion:

1. A planet orbiting the sun. 

2. Merry- go round.

Oscillatory motion:

1. Pendulum of clock.

2. Motion of swing.

10. Observe different objects around you. It is easier to express  the lengths of some objects in mm, some in cm and some in  m. Make a list of three objects in each category and enter  them in the Table 5.6. 

Schoolvally answer:

Size   -    Objects 

mm    -    Thickness of pencil lead. Thickness of notebook. 

cm     -     Length of pencil, Length of science text book.

m       -      Length of class room. Length of my friend.

 11. A rollercoaster track is made in the shape  shown in Fig. 5.19.  A ball starts from  point A and escapes  through point F.  Identify the types of  motion of the ball  on the rollercoaster  and corresponding  portions of the track. 

Schoolvally answer:

1. Point A to B and point E to F- Linear Motion.

2.  Point C to E Circular motion.

 12. Tasneem wants to make a metre scale by herself. She  considers the following materials for it—plywood, paper,  cloth, stretchable rubber and steel. Which of these should  she not use and why? 

Schoolvally answer:

Stretchable rubber is not suitable because it is flexible and can change length due to stretching. This would make it difficult to maintain accurate measurements. 

13. Think, design and develop a card game on conversion of  units of length to play with your friends. 

Schoolvally answer: 

The name of the game is Conversion Expert.

A deck of cards will have kilometers and other deck its conversion in meters.

One player will throw a card  the other will have to counter it with the exact conversion card.

Q1.   Can you find the thickness of a single page of your notebook  or textbook using a scale? Think of a way and write it. Carry  out the activity and report your result. 

Schoolvally answer:

No, I can not measure the thickness of a single page of your notebook or textbook  using a scale, because the minimum length that can be measured using scale is 1mm and the thickness is far less than that.

If i have to measure the thickness using the scale. 

Step 1- 

I can bundle some pages and see how many pages make 1mm.

Step 2-

Count the pages and divide it with 1mm, this will give you the thickness.

10 pages = 1mm thick

1 page is 0.1 mm thick

Q2.   Discuss with elders in your community what units were  used for measurement of length in the olden days. Also,  using the internet, try to find out about the length scales found in excavations of archaeological sites in India.

Schoolvally answer:

1. Balisht :   Handspan. 

2. Angula : Finger width.

3. Dhanusa :  3 Meters (modern)

4. Yojan :  12.2 kms (modern)

EQ1. Define SI System?

Schoolvally answer:

 The International System Of Units (SI) is the metric system that is used universally as a standard for measurements. SI units play a vital role in scientific and technological research and development. 

 1 km = 1000 m, 1 m = 100 cm, 1 cm = 10 mm. 

 The SI unit of length is metre. Its symbol  is m. A metre scale is shown in Fig. 5.2. One  metre (m) is divided into 100 equal divisions.  Each division is called a centimetre (cm). 

EQ 2. Define reference point?

Schoolvally answer:

 When distance is stated with respect to a fixed object or  point, then this point is called a reference point.

EQ 3. Define Motion and Rest? 

Schoolvally answer:

 An object is said to be in motion if its position changes  with respect to the reference point with time. If an object is  not changing its position with respect to the reference point  with time, it is said to be at rest.

EQ 4. What are types of motion?

Schoolvally answer:

 There are mainly 3 types of motion as under-

1.  Linear Motion: When an object moves along a straight line, its motion is  called linear motion or Rectilinear motion. 

 For example: March pass of soldiers.

2.  Circular motion: When an object moves along a circular path, its motion is  called circular motion. 

 For Example: Merry go round.

3. Oscillatory motion:

 When an object moves to and for about some fixed  position, its motion is called oscillatory motion or periodic motion.

For example: Pendulum of clock. 

1.  Find the companion. Link the following words by putting arrows between words  that have a connection. 

Schoolvally answer:

Iron -  Solid

Transparent - Glass 

Copper -  Lustrous 

Bottle - Plastic 

Wood - Opaque

2. Win the ‘Word-hub’ The following words from the chapter like lustrous, non lustrous, soluble, insoluble, hard, soft, matter, mass,  transparent, opaque, volume and translucent are picked up. 

Students should randomly choose nine words from the given  list and write them in the grid. Then, the facilitator either reads the definition of a word or  the word itself (randomly) from the given list.. The learners have to tick if the particular word is there in  the grid. Whoever finishes ticking off all nine words first will shout  out ‘Hurray!’. That person will be the winner if his/her words  are marked correctly. 

Schoolvally answer:  

Lustrous: Shiny.

Non-lustrous: Dull.

Soluble: Dissolves in a liquid.

Insoluble: Does not dissolve in a liquid.

Hard: Difficult to scratch or dent.

Soft: Easily scratched or dented.

Matter: Anything that occupies space and has mass.

Mass: Amount of matter in an object.

Transparent: Allows light to pass through clearly.

Opaque: Does not allow light to pass through.

Volume: Space occupied by matter.

Translucent: Allows some light to pass through, but not clearly.

 1. Visit your kitchen and observe how your parents have  organised various edibles. Can you suggest a better sorting  method? Write it in your notebook. 

Schoolvally answer:

Yes, the better way could be to arrange them size wise. smaller nearer to hands. and heavy farther. Also packets can be kept over the  big boxes.

 2. Unscramble the letters (Column I) and match with their  properties (Column II). 

 Column I Column II  

(i) T R E M A T (a) Objects can be seen  clearly through it  

(ii) U L S B E L O (b) Occupies space and  has mass 

(iii) T N E R P A S N A R T (c) Shiny surface 

(iv) E R U S T L (d) Mixes completely in water

Schoolvally answer:

The unscrambled list and their matching properties are as under:

T R E M A T - Matter

U L S B E L O - Soluble

T N E R P A S N A R T - Transparent

E R U S T L - Lustre or Lustrer

 3. The containers which are used to store materials in shops and  at home are usually transparent. Give your reasons for this. 

Schoolvally answer:

Containers are often transparent so you can easily see the contents, making it convenient to identify and access what’s inside without opening them.

4. State whether the statements given below are True [T] or  False [F]. Correct the False statement(s).

Schoolvally answer: 

(i) Wood is translucent while glass is opaque. [ False ]  

(ii) Aluminium foil has lustre while an eraser  does not. [ True ] 

(iii) Sugar dissolves in water whereas sawdust  does not. [ True ] 

(iv) An apple is a matter because it occupies no  space and has mass. [ True  ] 

5. We see chairs made up of various materials, such as wood,  iron, plastic, bamboo, cement and stones. Following are  some desirable properties of materials which can be used  to make chairs. Which materials used to make chairs fulfil  these properties the most? 

 (i) Hardness (does not bend or shake on sitting even after  long use). 

(ii) Lightweight (easy to lift or to take from one place to  another). 

(iii) Does not feel very cold when sitting during winters. 

(iv) Can be cleaned regularly and made to look new even  after long use. 

Schoolvally answer:

Here's how the materials commonly used for making chairs fulfill these properties:

(i) Hardness: Wood, iron, cement, and stones are ideal as they provide sturdy support and do not bend or shake with prolonged use.

(ii) Lightweight: Plastic and bamboo are the best options as they are easy to lift and move around.

(iii) Does not feel very cold: Plastic, Wood and bamboo are preferable because they feel warmer and more comfortable during cold weather.

(iv) Can be cleaned regularly: Plastic, wood, and metal (like iron) are easy to clean and maintain their appearance over time.

6. You need to have containers for collection of 

(i) food waste,  

(ii) broken glass and 

(iii) wastepaper. 

Which materials will  you choose for containers of these types of waste? What  properties of materials do you need to think of? 

Schoolvally answer:

 (i) Food Waste:

• Material: Plastic or metal (with a lid)
• Properties: Durability, resistance to moisture and odors, and ease of cleaning.

(ii) Broken Glass:

• Material: Strong plastic or metal (with reinforced edges and tight lid)
• Properties: Strength, impact resistance, and safety (to prevent cuts).

(iii) Wastepaper:

• Material: Cardboard or plastic
• Properties: Lightweight, ease of handling, and recyclability.

7. Air is all around us but does not hinder us from seeing each  other. Whereas, if a wooden door comes in between, we  cannot see each other. It is because air is  and the wooden door is . Choose the most  appropriate option:  

(i) transparent, opaque   

(ii) translucent, transparent 

(iii) opaque, translucent 

(iv) transparent, translucent 

Schoolvally answer:

  (i) transparent, opaque  

 Air is transparent, meaning it allows light to pass through, so we can see through it. 

A wooden door is opaque, meaning it blocks light and prevents us from seeing through it. 

8. Imagine you have two mysterious materials, X and Y. When you try to press material X, it feels rigid and does not change  its shape easily. On the other hand, material Y easily changes  its shape when you press it. Now, when you mix both  materials in water, only material X dissolves completely,  while material Y remains unchanged. What can materials  X and Y be? Can you identify whether material X is hard or  soft? What about material Y? Justify your answer.  

Schoolvally answer:

Material X: Dissolves completely in water, is rigid, and does not easily change shape. 

This means that Material X is a hard, soluble substance, likely to be something like lump of salt or sugar.

Material Y: Changes shape easily when pressed and does not dissolve in water. This means that Material Y is a soft, insoluble substance, such as clay or rubber.

9. (i) Who am I? Identify me on the basis of the given  properties. 

• (a) I have lustre.  
• (b) I can be easily compressed. 
• (c) I am hard and soluble in water. 
• (d) You cannot see clearly through me. 
• (e) I have mass and volume but you  cannot see me.

Schoolvally answer:

 Qualities like lustre, solubility, and opacity,  It could is crystalline sugar 

( Mishri  ) or Rock Salt.

Sugar / Rock salt has a lustrous appearance.

Sugar / Rock salt Cannot be easily compressed.

Sugar / Rock salt is hard and soluble in water.

Sugar / Rock salt is opaque in its solid form.

Sugar / Rock salt In solution, it has mass and volume but is not visible as solid crystals.

(ii) Create your own ‘Who am I?’:

Here’s an example:

• (a) I am transparent.
• (b) I am a liquid.
• (c) I can dissolve many substances.
• (d) I have no distinct smell or taste.
• (e) I am essential for life.

Who am I?

Answer: Water

10. You are provided with the following materials—vinegar,  honey, mustard oil, water, glucose and wheat flour. Make any two pairs of materials where one material is  soluble in the other. Now, make two pairs of materials where  one material remains insoluble in the other material. 

Schoolvally answer:

 Soluble Pairs:

1. Glucose and water
2. Honey and water
3. Vinegar and water

Insoluble Pairs:

1. Mustard oil and water
2. Wheat flour and vinegar

1.  Gather information on different materials which can be  recycled. You can take help from various sources such as  newspapers, magazines, talking to elders in your community,  and the internet. 

Schoolvally answer:

• Paper: Newspapers, magazines, cardboard.
• Glass: Bottles, jars.
• Plastic: Bottles, containers.
• Metal: Cans, aluminum, steel.
• Electronics: Phones, computers.
• Textiles: Clothing, linens.
• Rubber: Tires, mats.
• Organic Waste: Food scraps, yard waste.

2. Recyclers buy old objects based on properties of the  materials and do not bother even if an object is broken.  Conduct a survey with recyclers near you and find out what  properties of materials they check before buying objects  from households. Which materials do they not buy and why? 

Schoolvally answer:

Properties Checked:

1. Material type

2. Condition

3. Purity

4. Market value

Materials Not Bought:

1. State food

2. Plastics bags

3. Explosives

4. Old ropes

3.  Collect 20–30 objects from your household and classify  them based on the properties of the materials they are  made up of. Were you able to put them in separate groups?  What relationship do you see between the properties of the  materials and the use of the objects? 

Schoolvally answer:

Classification of Objects:

1. Paper : Newspapers, notebooks, cardboard.

2. Plastic : Bottles, containers, bags.

3. Metal : Cans, utensils, tools.

4. Glass : Jars, bottles, mirrors.

5. Wood : Furniture, shelves, toys.

6. Textiles : Clothing, towels, rugs.

Observations:

- Objects are grouped based on their material properties. 

For example paper items are lightweight and recyclable, metal items are durable and can be recycled.

- The material properties often relate to the object’s use.

 For example plastic is used for containers due to its flexibility, metal for tools due to its strength).

4.  Create and decorate a useful object of your choice using  discarded materials and bring it to the class. Discuss with your  friends what they have made and the materials they have  used. Additionally, provide constructive feedback on areas for  improvement, considering functionality and any other points. 

Schoolvally hint:

Cut old water bottle from middle neatly and decorate with colorful tapes and make a pen stand out of it.

Ques1.  Define Classification?

Schoolvally answer:

 The method of arranging the objects into groups is called  classification. Objects can be classified on the basis of a  common property that they have. We can classify materials based on certain  properties .

Ques2. Define Lustrous?

Schoolvally answer:

 Materials that typically have shiny surfaces are said to  have a lustrous appearance. Such materials with luster are  usually metals. Examples of metals include iron, copper, zinc,  aluminium, gold, etc. 

Sometimes  metals may lose their  luster and start to look dull or non-lustrous due  to the effect of air and moisture on them.  

Ques3.Define  Non-lustrous ?

Schoolvally answer:

 Non-lustrous materials are those that do not have a shiny  surface. Some examples of non-lustrous  materials are paper, wood, rubber, jute, etc 

Ques4. Define Soft Material?

Schoolvally answer:

 Materials which can be compressed or  scratched easily are soft materials.  However, these  properties are relative in nature. For example, rubber is  harder than sponge but softer than iron 

Ques4. Define Hard Material?

Schoolvally answer:

 materials which are  difficult to compress or scratch are hard material.  However, these  properties are relative in nature. For example, rubber is  harder than sponge but softer than iron. 

 Activity 6.5: Let us observe

 Hold the objects given in Table 6.3 with your hands. Feel whether the objects are hard or soft. Find out the  materials they are made up of. Enter your observations  in Table 6.3  

 Object - Hard/Soft - Material(s) 

Brick - Hard - Baked clay  

Water bottle - Hard - Plastic

Pillow - Soft - Cotton

Tumbler - Hard - Glass

Table - Hard - Wood

Sweater - Soft - Wool

Chalk - Hard - Lime

Ques 5 . Define transparent?

Schoolvally answer:

 The materials, through which things can be seen clearly,  are called transparent. Glass, water, air, cellophane paper,  etc., are some examples of transparent materials.

Ques 6 .Define Opaque?

Schoolvally answer:

Materials through which you are not  able to see at all. These materials are called opaque. For example Wood, cardboard and metals.

Ques 7. Define translucent?

Schoolvally answer:

 The materials through which objects can be seen partially and not clearly, are known as translucent. Butter paper and frosted  glass, colored plastic sheet are examples of translucent materials. 

 Activity 6.6: Let us classify 

 Classify the following objects as transparent, translucent or  opaque in Table 6.4. 

Schoolvally answer:

1. Glass tumbler -  transparent

2.  Butter Paper -  translucent

3.  Eraser - Opaque

4. Frosted glass - translucent

5. Wooden board -  Opaque

6. Window glass - transparent 

 Activity 6.7: Let us explore 

 Table 6.5: Mixing different materials in water 

Schoolvally answer:

Material -- Sugar 

Prediction - Will disappear  in water 

Observation - Will disappear  in water 

Material -- Salt 

Prediction - Will disappear  in water 

Observation - Will disappear  in water

Material -- Chalk Powder

Prediction - Does not disappear  in water 

Observation - Does not disappear  in water

Material -- Sand

Prediction - Does not disappear  in water 

Observation - Does not disappear  in  water

Material -- Saw dust

Prediction - Does not disappear  in water 

Observation - Does not disappear  in water

Material -- Ink

Prediction - Will disappear  in water 

Observation - Will disappear  in water

Ques8. Define soluble and Insoluble?

Schoolvally answer:

Materials that dissolve in water and disappear then mixed are known as soluble materials. It is not easy to separate soluble material.

Example -Milk is soluble in water.

Materials that do not  mix with water and do not disappear even  after we stir them for a long time. These  materials are insoluble in water. It is relatively easy to separate insoluble material.

Example- Oil is insoluble in water.

Ques 9. Define Volume?

Schoolvally answer:

 Volume is defined as the space occupied within the boundaries of an object in three-dimensional space. In other words it is the capacity of the object.

1 L, 500 ml etc. on the water bottles indicate the volume of the bottle.

Ques 10. Define Matter? 

Schoolvally answer:

 Matter is anything that takes up space and can be weighed. In other words, matter has volume and mass.

 The mass gives the quantity of matter,  and the units to measure it are gram (g) and kilogram (kg). 

 Materials are types of matter used in the  creation or making of objects 

1. The normal temperature of a healthy human being is close to .

(i) 98.6 °C

(ii) 37.0 °C  

(iii) 32.0 °C

(iv) 27.0 °C

Schoolvally answer:

(ii) 37.0 °C  

2. 37 °C is the same temperature as   .

(i) 97.4 °F 

(ii) 97.6 °F

(iii) 98.4 °F

(iv) 98.6 °F

Schoolvally answer:

 (iv) 98.6 °F 

3. Fill in the blanks: 

Schoolvally answer:

(i) The hotness or coldness of a system is determined by its 

(ii) The temperature of ice-cold water cannot be measured by a   thermometer.

(iii) The unit of temperature is degree  .

Schoolvally answer:

 (i) The hotness or coldness of a system is determined by its Temperature         . 

(ii) The temperature of ice-cold water cannot be measured by a clinical                               . thermometer.

(iii) The unit of temperature is degree  Celsius or centigrade        .

4. The range of a laboratory thermometer is usually  .

(i) 10 °C to 100 °C

(ii) –10 °C to 110 °C

(iii) 32 °C to 45 °C

(iv) 35 °C to 42 °C

Schoolvally answer:

 (ii) –10 °C to 110 °C  

5. Four students used a laboratory thermometer to measure the temperature of water as shown in Fig. 7.6: Student 1 Student 2 Student 3 Student 4 Fig. 7.6

Who do you think followed the correct way for measuring temperature?

(i) Student 1

(ii) Student 2 

(iii) Student 3

(iv) Student 4

Schoolvally answer:

(ii) Student 2

6. Color to show the red column on the drawings of thermometers (Fig. 7.7) as per the temperatures written below:

Schoolvally hint:

Fig 1 = Color In between 10 and 20

Fig 2 = Color In between 15 and 20

Fig 3 = Color In between 0 and 10

7. Observe the part of thermometer shown in Fig. 7.8 and answer the following questions: Fig. 7.8  

(i) What type of thermometer is it?

(ii) What is the reading of the thermometer?

(iii) What is the smallest value that this thermometer can measure?

Schoolvally answer:

 (i) What type of thermometer is it?

Laboratory thermometer.

(ii) What is the reading of the thermometer?

26.0 °C

(iii) What is the smallest value that this thermometer can measure? 

-10.0 °C

8. A laboratory thermometer is not used to measure our body temperature. Give a reason.

Schoolvally answer:

1.  A laboratory thermometer is calibrated differently.

2. A laboratory thermometer is difficult to handle due to its big size .

3. A laboratory thermometer does not have 'kink' so the mercury level falls quickly, before one can take the reading.

4. A laboratory thermometer needs to be   kept in up right position only. This means the patient needs to lie straight every time. Which could be uncomfortable for patient.

9. Vaishnavi has not gone to school as she is ill. Her mother has kept a record of her body temperature for three days as shown in Table 7.4. Body temperature record of Vaishnavi Temperature at

DAY 7am 10am 1pm 4pm 7pm 10pm

One 38.0 °C 37.8 °C 38.0 °C 38.0 °C 40.0 °C 39.0 °C

Two 38.6 °C 38.8 °C 39.0 °C 39.0 °C 39.0 °C 38.0 °C

Three 37.6 °C 37.4 °C 37.2 °C 37.0 °C 36.8 °C 36.6 °C

Schoolvally answer:

(i) What was Vaishnavi’s highest recorded temperature?

The highest temperature is 40.0 °C

(ii) On which day and at what time was Vaishnavi’s highest temperature recorded?

Vaishnavi’s highest temperature was  recorded on Day one at 7 PM.

(iii) On which day did Vaishnavi’s temperature return to normal?

Vaishnavi's temperature return to normal on Day three at 4.0PM  which is 37.0 °C  

10. If you have to measure the temperature 22.5 °C, which of the following three thermometers will you use (Fig. 7.9)? Explain.

Schoolvally answer:

I will choose 'a' because it is neat and clean calibration and a slim design.

11. The temperature shown by the thermometer in Fig. 7.10 is

(i) 28.0 °C

(ii) 27.5 °C

(iii) 26.5 °C

(iv) 25.3 °C 

Schoolvally answer:

(ii) 27.5 °C

12. A laboratory thermometer has 50 divisions between 0 °C and 100 °C. What does each division of this thermometer measure? 

Schoolvally answer:

Each division of this thermometer measure 2.0 °C.

Formula:  50  x  2 = 100

13. Draw the scale of a thermometer in which the smallest division reads 0.5 °C. You may draw only the portion between 10 °C and 20 °C.

Schoolvally hint:

Make 20 equal calibration. Each part will be 0.5 °C.

14. Someone tells you that she has a fever of 101 degrees. Does  she mean it on the Celsius scale or Fahrenheit scale? 

Schoolvally answer:

It means in  Fahrenheit  scale  (101°F) . 

Q. Gather information from the Internet and find out how the body temperature of animals, such as a cat, dog, horse, camel, cow and buffalo, is measured. If there is any veterinary hospital in your vicinity, you may visit to see the body temperature of animals being measured.

Schoolvally answer:

I visited the Animal hospital in my vicinity. the thermometer is inserted in the anus and hold there for half a minute, this is how the temperate is measured in animals.

Different animal have different normal temperatures as based on a discussion with a veterinary doctor: 

Dogs: 101-102.5°F (38.3-39.2°C) 

Cats: 100.5-102.5°F (38.1-39.2°C) 

Cows: 101.5°F (38.6°C)

  
Q. Find out which places in India are usually regarded to be the coldest and hottest. Also, find out the minimum and the maximum temperatures recorded for these places. 

Schoolvally answer:
Coldest place Siachen Glacier, Ladakh

-50 degrees

Hottest place is Mungeshpur Delhi. 

 Q  Various planets in our Solar System are at different distances from the Sun. Search the Internet and make a table with the planets, their distances from the Sun (in increasing order) and their temperatures written. Does the average temperature of planets decrease as their distance from the Sun increases? If it is not true for any planet, find out for which planet and why.  

Schoolvally answer: 

 In order of distance from the sun they are; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto.

The nearer he planet to the sun higher the temperature, but the atmosphere of the planet also plays an important role, 

 
Q.  Hang a room thermometer in your classroom. Set up the apparatus, as shown in Fig. 7.11, near the thermometer hung on the wall. 

Take the readings of thermometers 1 and 2 three times during the day, say, first period, lunch break, and last period. 

Record your readings. Compare the readings and draw your conclusions. Repeat this for two weeks. 

Schoolvally hint:

The readings will be increasing in both.

The reading of thermometer 2 will be less.

 EQ. Can it always be correctly judged that a person has fever only by touching the person?

Schoolvally answer:

No, it cannot be correctly judged that a person has fever only by touching the person. 

EQ. Activity 7.1: Let us investigate Write down your predictions.

Schoolvally answer: 

What will my right hand feel on dipping in B.

Prediction: It will feel Cold.

What will my left hand feel on dipping in B.  

Prediction It will feel Warm.

Now, conduct the activity and write your  observations.

Right hand feels Cold

Left hand feels Warm

EQ. What do you infer  form these observations:

Schoolvally answer:

 We cannot always rely upon our sense of find out how hot or cold a body is hot or cold. 

I saw that the same water was felt warm by one hand and cold by another hand. This made me confused should i say water in container B is hot or cold :(

EQ. What is temperature?

Schoolvally answer:

A reliable measure of hotness (or coldness) of a body is its temperature. 

A hotter body has a higher temperature than a colder body. 

In other words the degree of hotness and coldness of the body is known as temperature and is measured with a thermometer in two ways degrees Fahrenheit or degrees Celsius these are called units of temperature. 

EQ. What is a thermometer? 

Schoolvally answer: 

A device that measures temperature is called a thermometer.

EQ. What are different types of 

thermometer? 

Schoolvally answer:

There are two kinds of thermometers: Clinical thermometers- Clinical thermometers are used to measure human body temperatures.

laboratory thermometers- laboratory thermometers are used for many other purposes.

EQ. What is digital thermometer?

Schoolvally answer:

The thermometers that show temperature digitally are called digital thermometer they run on small batteries and are convenient to use.

  These measure temperature when the thermometer is placed in contact with a person’s body.

For measuring temperature, the clinical thermometers generally use a scale called the Celsius scale and is denoted by °C.   

EQ. What is the difference between old mercury thermometer and digital thermometer?

Schoolvally answer:

Differences:

1. Mercury thermometer user toxic mercury

2. Mercury thermometer is brittle and easily breakable.

3. Temperature is determined by expansion of mercury in glass capillary marked up to scale.

4. Reading the scale needs training and is not convenient to use.

Digital thermometer:

1. Digital thermometer does not uses any thing toxic.

2. Digital thermometer is strong and is made of Bakelite.

3. Temperature is determined with the help of heat sensors.

4. A digital thermometer is simple and convenient to use does not need any special training.

EQ. What are not-contact thermometers?

Schoolvally answer:

These are special type of thermometers which could measure the temperature of a person from a distance. 

They use infrared rays. They are useful when there is outbreak of a communicable disease, thus reduce the risk of spreading disease.

EQ. What is the temperature of healthy human being?

Schoolvally answer:

The normal temperature of a healthy human body is taken to be 37.0 ° Celsius / Centigrade or 98.6° Fahrenheit. 

EQ. How to convert 37.0 degree to Fahrenheit?

Schoolvally answer:

Formula is

(37°C × 9/5) + 32 = 98.6°F

EQ. What Influences the temperature of a healthy person?

Schoolvally answer:

The body temperature is influenced by several factors, such as age, time of the day and activity level. However the   

The temperature of human beings does not normally go below 35 °C or above 42 °C. 

EQ. What is the SI unit of temperature?

Schoolvally answer: 

The Fahrenheit scale is not used in most scientific studies anymore. In scientific work, there is another scale of temperature known as  Kelvin scale. On this scale, the unit for temperature is kelvin and is denoted by K.

So we can say that the the SI unit of temperature is kelvin.

EQ. How can we convert Kelvin to Celsius?

Schoolvally answer: 

Temperature in degrees Celsius is obtained by subtracting 273.15 from the numerical value of the temperature expressed in kelvin.

EQ.  What is a Laboratory thermometer? 

Schoolvally Answer: 

It consists of a long, narrow, uniform glass tube which is sealed. At one end of the tube is a bulb which contains a liquid. Outside the bulb, in the tube, a narrow column of liquid can be seen. There is a Celsius scale marked along the tube. The liquid column rises or falls with change in temperature. The mark of the Celsius scale with which the top level of the liquid column coincides is the temperature reading. Its  range is from –10 °C to 110 °C.

EQ. What is air temperature?

Schoolvally Answer:

 Air temperature is the temperature of the air surrounding an individual and is typically measured in degrees Celsius (°C) or degrees Fahrenheit (°F).

1. Which of the following best describes condensation?

(i)   Activity Which o the following best describes condensation?

(ii) The process of water changing from a liquid into gaseous state.

(iii) The formation of clouds from tiny water droplets.

 (iV) The conversion of water vapour into its liquid state.

Schoolvally answer:

(iV) The conversion of water vapour into its liquid state.

  2.iDentify in which of the given processes, evaporation is very important—

(i) Colouring with 

(a) crayons    (b) water colours  (c) acrylic colours  (d) pencil colours 

Schoolvally answer:

 (b) water colours 

(ii) Writing on paper with 

(a) pencil  (b) ink pen  (c) ball point pen

 (b) Ink pen

3. We see green coloured plastic grass at many places these days. Space around natural grass feels cooler than space around the plastic grass. Can you find out why?

Schoolvally answer:

 The space around natural grass feels cooler than around plastic grass because natural grass cools through transpiration, The process by which water comes out of leaves of plants. This water then evaporates, Hence cooling the atmosphere.

4.  Give examples of liquids other than water, which evaporate.

Schoolvally answer:

Examples of liquids that evaporate:

• Alcohol (e.g., ethanol)
• Acetone
• Petrol
• kerosene
• Nail polish remover
• Milk
• Cold drink

5. Fans move air around, creating a cooling sensation. It might seem strange to use a fan to dry wet clothes since fans usually make things cooler, not warmer. Normally, when water evaporates, it requires heat, not cold air. What do you think about this? 

Schoolvally answer:

 A fan helps dry clothes by increasing air movement, which speeds up evaporation. Although fans don’t heat the air, they enhance the evaporation rate by moving moist air away from the clothes and replacing it with drier air. 

6. Usually, when sludge is removed from drains, it is left in heaps next to the drain for 3–4 days. Afterward, it is transported to a garden or a field where it can be used as manure.

This approach reduces transportation cost of the sludge and enhances the safety of individuals handling it. Reflect upon it and explain how. 

Schoolvally answer:

 Leaving sludge to dry out before transport reduces weight and volume, which makes it lighter, hence cuts transportation costs and minimizes handling risks. 

Dried sludge can be safely used as manure, improving soil quality. 

This happens due to the process of evaporation.

7. Observe the activities in your house for a day. Identify the activities that involve evaporation. How does understanding the process of evaporation help us in our daily activities?

Schoolvally answer:

There are many house hold activities that involve evaporation like:-

• Drying dishes.
• Drying clothes.
• Cooling of Milk.
• Cooling of garden.

 Understanding the process of evaporation help us in our daily activities as with this knowledge we can control the moisture level of food items and prevent them form getting spoil.

• With the knowledge of evaporation we can distil the water and use it.
• With the knowledge of evaporation we can make our surrounding cooler etc.

8. How is water present in the solid state in nature? 

Schoolvally answer:

Water in solid form is ice. Examples include glaciers, snow, and frost. 

9. Reflect on the statement “Water is our responsibility before it is our right.” Share your thoughts. 

Schoolvally answer:

 This statement emphasizes that we should manage and conserve water responsibly because it’s a precious resource that needs protection for future generations. 

10. The seat of a two-wheeler parked on a sunny day has become very hot. How can you cool it down?

Schoolvally answer:

We  can place a damp cloth on it. The water on the cloth will evaporate, absorbing heat from the seat and cooling it down. 

Ques: Wet one hand with water and leave the other dry. Blow air across both hands and feel the cooling effect. Find out the reasons for it.

Schoolvally answer:

Wetting one hand and blowing air across both hands demonstrates that evaporation of water from the wet hand happens this absorbs heat, causing a cooling effect. 

Ques: Make a game to navigate through different states of water and water related concepts to reach the finish line. Challenge cards with questions related to water cycle, evaporation, condensation, etc., can be some game elements. 

Schoolvally hint:

Create a board game with questions and challenges about the water cycle, states of water, and related concepts. Players advance or move forward by answering correctly, with the goal of reaching the finish line.

Ques: Discuss with your teacher and act out the stages of the water cycle through a role-playing activity in your school assembly.

Schoolvally hint: 

To act out the water cycle, students can role-play different stages like evaporation, condensation, precipitation, and collection, One person will hold a banner, simulating how water moves. they can do actions and make sounds to illustrate through these stages in a fun and educational way.

1.  Activity 8.1: Let us observe Put an ice cube in a cup, leave it on the table and observe. Ice gets converted into water.

A. What can you conclude from the observations?

Schoolvally answer:

From this observation we can conclude that ice is made up of water.

B. Does this mean that ice and water are the same substance?

Schoolvally answer:

Yes, this means the basic element of ice and water is same. Ice and water are the two forms of the same substance. 

Activity 8.2: Let us investigate

A. Take a tablespoon of water on a steel plate as shown in Fig. 8.1. Observe whether water seeps through to the other side of the plate or not.

Schoolvally answer:

No water does not seeps through to the other side of the plate.

C. Keep observing this at regular intervals until the water completely disappears. What do you Infer?

Schoolvally answer:

We Infer that the water gets converted into vapors and mixes with surrounding air.

Q. Hand sanitiser disappears as you rub it on your hands. 

What happens to it? 

Schoolvally answer:

 The sanitizer comes out as liquid, but after some time, it starts to disappear. It's not all soaking into your skin that quickly; it's evaporating! Changing from a liquid to a gas (evaporating).

C. Activity 8.3: Let us experiment  Take cold water in a glass tumbler.

Add a few ice cubes into it as shown in Fig. 8.2.

Leave it undisturbed for five minutes and observe it.

Record your observations and the questions that arise in your mind

in Table 8.1. You can also touch the outer surface of the glass tumbler to  feel if there is any change. 

Schoolvally answer:

I observe: The glass tumbler is cold.

I observe: The glass tumbler is wet.

I observe: The glass tumbler is slippery.

I wonder: How the water seeped out of glass tumbler?

Q. Suggest possible reasons explaining the appearance of water droplets on the outer surface of the glass tumbler. 

Schoolvally answer:

Since, the glass tumbler is not having any cracks, i think the water vapors  form the 

surrounding are getting attracted to the glass tumbler.

Activity 8.11: Let us understand the process. Label Fig. 8.9 using arrows shown and the words given in the box to show where water is stored, how water changes its state and where it moves. Cloud, Lake, Ocean, River, Groundwater, Evaporation, Condensation, Rain, Snow

Schoolvally answer:

Draw the diagram and make the arrows as in water cycle.

Q. Discuss with your friends. Write down the possible reasons in Fig. 8.3.

Schoolvally answer:

1. May be ice has come out of glass tumbler.

2. May be the water seeped through the glass tumbler.

Q. Where else have you seen the water droplets like this?

Schoolvally answer:

I have seen such droplets on the bottle of cold drink.

I have also seen such droplets on the tap of our water cooler in school.

I have seen such droplets on flowers and leaves in winters.

 Activity 8.4: Let us measure  

 Take a glass tumbler half-filled with water containing a few ice cubes. Cover it with a small steel plate. Weigh it on a digital weighing balance. Observe the reading on the balance and record the weight after every five minutes.

Continue observing for 30 minutes. Record your observations in Table 8.2.

Schoolvally answer:

 Time -----  Mass of water 

0 min----200.00 gms

5 min----200.01 gms

10 min----200.02 gms

15 min----200.03 gms

20 min----200.05 gms

25 min----200.07 gms

30 min----200..09 gms

There was a change in the mass of the apparatus under observation, there were visible water drops on the outer surface of the glass.

Q. Predict what will happen to the mass of cold water kept on the digital weighing balance. Will it increase or decrease or remain the same? 

Schoolvally answer:

It will increase.

EQ1. What is Evaporation?

Schoolvally answer:

The process of conversion of water into

its vapor state is called evaporation.

EQ2. What is water vapor?

Schoolvally answer:

The water vapor is another state of water. When water gets converted into gaseous state it is called water vapor.

EQ3. What is Condensation?

Schoolvally answer:

 The process of conversion of water vapour into its liquid state is called condensation.  

When the water vapor present in the air comes in contact with a cold surface, 

it forms water droplets. Condensation is reverse on evaporation.  

 1. What purpose does handpicking serve in the process of  separation?  

(i) Filtration 

(ii) Sorting

(iii) Evaporation 

(iv) Decantation

Schoolvally answer: 

 (ii) Sorting 

2. Which of the following substances are commonly separated  using the churning method?  

(i) Oil from water 

(ii) Sand from water 

(iii) Cream from milk 

(iv) Oxygen from air

Schoolvally answer:

 (iii) Cream from milk

3.  Which factor is usually essential for the filtration?  

(i) Apparatus size 

(ii) Presence of air 

(iii) Pore size 

(iv) Temperature of the  mixture 

Schoolvally answer:

 (iii) Pore size 

4. State with reason(s) whether the following statements are  True [T] or False [F]. Also, correct the False statement(s).  

Schoolvally answer:

(i) Salt can be separated from salt solution by  keeping it under the Sun. 

[ True ]  

(ii) Handpicking should be used only when the  quantity of one component is less. [ False] 

(iii) A mixture of puffed rice and rice grains can be separated by threshing. 

[False ] 

(iv) A mixture of mustard oil and lemon water can  be separated by decantation. [True ]  

 (v) Sieving is used to separate a mixture of rice flour and water. 

[False ]

5. Match the mixtures in Column I with their method of  separation in Column II 

Schoolvally answer:

 Column I --------  Column II  

(i) Gram flour mixed with  black gram -  (a) Handpicking   

(ii) Chalk powder mixed with  water  -  (e) Filtration 

(iii) Corn mixed with potatoes  -  (d) Sieving 

(iv) Iron powder mixed with  sawdust  -  (b) Magnetic separation   

(v) Oil mixed with water  -  ( c) Decantation 

 6. In what situations would you use decantation instead of  filtration to separate solids from liquids? 

Schoolvally answer:

 Decantation and filtration are both methods used to separate solids from liquids, but they are suited to different situations based on the properties of the mixture.  

Decantation works best when there is a significant density difference between the liquid and the solid, allowing the solid to settle out effectively. For example, separating oil from water where the oil floats on top and can be poured off easily.

 If we want to separate fine particles and achieve high purity or achieve a higher degree of clarity in the liquid, filtration would be more appropriate. 

7. Can you relate the presence of nasal hair to any separation  process? 

Schoolvally answer:

 Nasal hair can be thought of as a natural filtration system for the respiratory system. It filters out larger particulates from the air, similar to how a physical filter captures solid particles from a liquid or gas in various separation processes. 

8. During the COVID-19 pandemic, all of us wore masks.  Generally, what material are they made of? What is the role  of these masks? 

Schoolvally answer:

 Masks used during the COVID-19 pandemic were generally made of cotton cloth and other surgical materials. They behaved like filters to the viruses.

 Their primary role was to reduce the spread of respiratory droplets from the wearer, protect others, and lower the transmission of the virus.

 9. A mixture containing potatoes, salt and sawdust has been  given to you. Outline a stepwise procedure for separating  each component from this mixture. 

Schoolvally answer:

The stepwise procedure for separating each component from the mixture is as follows:-

Step 1. Hand Picking- We will use hand picking to separate potatoes as they are visibly large and easy to identify.

 we will add water in the mixture of sawdust and salt and make solution.

Step2.  Decant and Filter: After letting it rest, pour off the water containing dissolved salt and floating sawdust, or use a filter to separate the sawdust from the water this will give pure saline water.

Step 3. Evaporation: Boil this solution till all the water evaporates, and we get the salt let this cool for some.

10. Read the following story titled ‘Intelligent Leela’ and tick the  most appropriate options. Provide a suitable title of your  choice for the paragraph. 

Schoolvally answer:

 Leela was working in the farm with her father when she realised  that they left their drinking water at home. Before her father  felt thirsty, * thirsty/hungry *

she went to the nearby pond to fetch some water * water/grains*.  

After obtaining some water in the container, she  noticed that the water was muddy and unfit * fit/unfit * for drinking. 

To  purify the water, she kept it for some time and then she filtered * filtered/ churned * the muddy water using a piece of muslin * paper/muslin * cloth.  

Leela, then, boiled * cooled/boiled * the water for about 10 minutes in  a covered pan. 

After cooling * cooling/boiling* ,she filtered * filtered/churned* it  again and made it fit * fit/unfit * for drinking. 

She served this water to her father while having food, who blessed her and appreciated  her efforts. 

Ques. Fun with parents: We are proud of our Indian heritage.  Under supervision of your elders, try to prepare some herbal  remedies using various parts of plants. For example—tulsi  kadha. Which methods of separation will you use while  preparing herbal kadha? 

Schoolvally answer:

We will use Sieving process.

Ques. Stage play: Imagine you and your friend are Malli and Valli.  Write dialogues of a play presenting their entire ‘Bharat ki  Yatra’, highlighting the different methods of separation of  substances that they observed. Enact the play in your school  assembly.

Schoolvally answer: 

Good morning friends !

I along with my friends went to a journey of Bharat and leaned about it amazing culture and the in-house technology used in house hold there. 

I must say our grand parents must have been genius. 

After this play you will also feel proud. In This is a play we will tell you what we saw and learned lets get started.  

Title: Bharat Ki Yatra: Palli, Malli and Valli's Exploration of household science.

Characters: of the play.

- Malli: A curious and adventurous child.

- Valli: Malli’s inquisitive and observant sister.

- Nani Maa: Malli and Valli’s maternal grandmother.

- Mamu: Malli and Valli’s maternal uncle.

- Mami Jaan: Malli and Valli’s maternal aunt.

- Ghanshyam Bhai: Father’s friend in Ahmedabad.

- Dadu: Paternal grandfather in Pune.

- Balan: Neighboring friend in Pune.

- Venketeshwara: Fisherman friend of Dadu.

“ Scene 1: At Nani’s House in Haryana”

(Malli and Valli are in the courtyard where grains are piled up. Their Mami Jaan and Mamu are working to separate stones and husk from the grains.)

Malli: Wow, look at all these grains! Why are Mami Jaan and Mamu picking out the stones and husk?

Nani: We’re handpicking the stones and husk to make the grains fit for cooking. This method is called handpicking. It’s effective when the unwanted particles are few and easy to pick by hand.

Valli: Oh, I see! It’s like when Malli separates the black peppers from the pulao at lunch.

Malli: Exactly! It’s handpicking in action. 

Nani: Yes, handpicking is useful for small quantities. But what if there were a lot more husk mixed with grains?

Malli: Then, we might need another method!

“Scene 2: In the Fields”

(Malli and Valli are with Mamu, watching farmers beating wheat stalks.)

Valli: What are the farmers doing?

Mamu: They are threshing the wheat. It’s the process of separating grains from the stalks. Threshing involves beating the stalks to release the grains.

Malli: And then?

Mamu: After threshing, the grains get mixed with husk. That’s where winnowing comes in.

“ Scene 3: Using the Winnowing Tray ”

(The next day, Malli and Valli see a farmer using a bamboo tray to separate husk from grains.)

Valli: How does the winnowing tray work?

Mamu: The farmer moves the tray in the direction of the wind. The lighter husk gets blown away while the heavier grains fall back into the tray. This method separates lighter components from heavier ones using the wind.

Malli: So, it’s like using the wind to separate the husk from the grains!

Scene 4: In Ahmedabad

(Valli is helping Mami Jaan prepare meethi puri and notices a sieve.)

Valli: How do you use this sieve?

Mami Jaan Jaan: We use the sieve to separate bran from flour. The fine flour passes through the sieve, while the larger particles like bran stay on top.

Malli: So, sieving is used when components of a solid mixture are of different sizes!

“ Scene 5: At Sabarmati Ashram ”

(Malli and Valli are with Ghanshyam Bhai who explains about obtaining salt from seawater.)

Ghanshyam Bhai: Seawater is evaporated to get salt. The water evaporates, leaving behind the salt.

Valli: That’s evaporation! We learned that when a liquid is heated, it turns into vapor, and the solid is left behind.

“ Scene 6: At Dadu’s House in Pune “

(Malli and Valli watch Dadu making tea and use a strainer.)

Dadu: We use a strainer to remove tea leaves from the tea. This process is called filtration.

Valli: And if there are still some tea leaves left?

Dadu: We can use decantation by letting the tea settle, then carefully pouring out the clear liquid. 

“ Scene 7: In Shillong ”

(Malli and Valli watch a carpenter using a magnet to separate iron nails from sawdust.)

Valli: Look, the magnet is attracting the nails out of the sawdust!

Malli: This is magnetic separation. The magnet pulls out magnetic substances from non-magnetic ones.

“ Scene 8: Final Thoughts ”

(Malli and Valli reflect on their journey.)

Malli: We’ve seen so many different ways to separate substances. Handpicking, threshing, winnowing, sieving, evaporation, decantation, filtration, and magnetic separation.

Valli: Each method is suited for different types of mixtures. It’s amazing how these methods are used in everyday life!

Malli: Yes, and it was fun learning them through our travels.

Valli: Absolutely! Our Bharat Ki Yatra was educational and exciting. 

Malli: Let's share all this knowledge with our friend’s back home!

Valli: Great idea! Our adventures and the methods we learned will make for a fantastic presentation.

*(Curtain falls as Malli and Valli prepare to share their experiences.)*

The End

 Ques. Group activity: Observe and list separation methods you  employed and noticed in your surroundings throughout a  week. Explain the reasons behind using these methods and  compile the ones you utilised or observed the most. Compare  your observations with your group members. 

Schoolvally answer:

I noticed following separation methods in my surrounding:-

1. Hand picking- The  kabadi walas separate different metals form the scrap and make heaps.

Reason: So the metals could be send for  recycling.

2.Sieving:- The chai-walals sieve the tea to separate the tea leaves .

Reason:-To filter out the tea leaves

3. The halwais boil chashni so water is evaporated and the  sugar syrup is  made sweeter and thicker.

Reason: Improve the quality.

Ques.  Be a stalwart of your community: Interview a ragpicker(s)  and prepare a case study about the method(s) of separation  he/she uses in his/her daily life. Encourage children of your  community below the age of 14 to join a neighbourhood  school. 

Schoolvally answer:

There  are  boys in my neighborhood who do rag picking early morning:

They use mainly two methods to sorting one is Handpicking and Magnetic separation.

They are school dropouts, they dropped from school as their elder brother and sister who are qualified could not find any job and joined their family business.

So, they decided to start early and start earning and help their family.

Ques. Be a reporter: (i) Gather newspaper clippings and articles  related to various methods of separation implemented in  your society, such as in agricultural fields or at construction  sites. (ii) Conduct interviews with local farmers to explore  the latest agricultural separation methods that they use.

Schoolvally answer: 

There are number of agricultural machines used to do the manual work like  Combine.

Combine is a harvesting machine which is mechanised in such a way that it performs reaping, threshing and winnowing of crops by use of this single machine only. Previously, when this machine was not invented, all procedures were performed by farmers only not it is not required thanks to the innovation in the field of Agricultural implements. 

Ques. Think like a scientist: You are provided with a mixture  of iron nails, sand, black pepper, stones, common salt  and water. Which steps will you follow to separate each  component of a mixture? 

Schoolvally answer:

Step 1. Magnetic Separation: This will remove nails for mixture.

Step 2. Handpicking: This will remove stones form the mixture.

Step 3. Decantation: This will remove the black pepper.

Step 4. Filtration: Filter the decanted water for any impurities , you will get saline water.

Step 5. Evaporation: By Boiling the water will evaporate and salt will settle in bottom.

Step 6. Drying: Let the sand dry and then collect it in a bag.

EQ. Define Decantation?
Schoolvally answer:

Decantation  It is the process of separation of a solid and liquid mixture or separation of mixtures of immiscible liquids. 

EQ. Define Filteration?

Schoolvally answer:

Filtration is the process of removing insoluble substances from the liquid by allowing them to pass through a filter paper.

1. List the similarities and differences in life cycles of plants  and animals. 

Schoolvally answer:

 A plant’s life cycle starts with seed germination, followed by  several stages of its growth and development. These includes  flowering and seed production. Seeds produced during their  life cycle would germinate into new plants and the cycle  continues. 

  The life cycle of an animal as a result of reproduction, begin  with a new born that undergoes various stages of growth and  development followed by an adult stage and finally death. The  process of reproduction maintains the continuity of its kind. 

 2. The table on the next page shows some data. Study the data  and try to find out examples appropriate for the conditions  given in the second and third columns  If you think that  an example for any of the conditions given below is not  possible, explain why .

Schoolvally answer:

 S. no. 1

Does it grow? ------ No

Does it  respire?  ---- No

Example --------Table

Remarks  ---Non Living

S. no. 2

Does it grow? ------- No

Does it  respire?  -------- Yes

Example -------  Nil

Remarks ------- Does not exit full fil characteristics of living and  non-living

S. no. 3

Does it grow? ----- Yes

Does it  respire? ------- No

Example ----- Nil

Remarks   ---------- Remarks Does not exit full fil characteristics of living and  non-living

S. no. 4

Does it grow? ----- Yes

Does it  respire? ------ Yes

Example ----- Human being

Remarks  Living being

 3. You have learnt that different conditions are required for  seed germination. How can we use this knowledge for  proper storage of grains and pulses? 

Schoolvally answer:

Yes, we know air, water and so times sunlight is required for germination. To store grains and prevent their germination. We can keep them in dry, cool, and airtight environments. 

4. You have  learnt that a tail is present in a tadpole but it disappears as it grows into a frog. What is the advantage of  having a tail in the tadpole stage? 

Schoolvally answer:

The tail in a tadpole helps with swimming and mobility in water, aiding in its survival and feeding. As the tadpole transitions to a frog, the tail is absorbed and repurposed for developing legs and other adult features.

5. Charan says that a wooden log is non-living as it cannot move.  Charu counters it by saying that it is living because it is made  of wood obtained from trees. Give your arguments in favour  or against the two statements given by Charan and Charu.  

Schoolvally answer:

 A wooden log is to be considered non-living because it does not exhibit the characteristics of life, such as movement, growth, respiration, respond to stimuli and reproduction. Although it originates from a living tree, the log itself does not possess life any more now and is dead wood.

6. What are the similarities and  distinguishing features in the life  cycles of a mosquito and a frog? 

Schoolvally answer:

The similarities in the life cycle of mosquito and frog is that their life cycle starts with Egg. Other similarity is that early stages of their life they live in water.

 In some living beings, such as mosquitoes and frogs, significant distinguishing features are seen or changes occur during the various stages of their life cycles. These changes can be seen in body shape,  structure and sometimes even in the habitat. 

 Mosquitoes pass through the stages of egg, larva, pupa  and adult. The life stages of a frog include eggs, tadpoles,  froglets and adults. 

7. A plant is provided with all the  conditions suitable for its growth (Fig. 10.9). Draw what you expect  to see in the shoot and the root of  the plant after one week. Write  down the reasons. 

Schoolvally answer:

The shoot of the plant will be taller and stronger and will grow upwards and  towards sunlight whereas the root will grow towards soil. 

The reason is that adequate light supports photosynthesis, which provides energy for growth. so stem grows towards light.

Water and nutrients are needed which comes from the soil so roots grow towards soil.

8. Tara and Vijay set up the  experiment shown in the picture  (Fig. 10.10). What do you think  they want to find out? How will  they know if they are correct?

Schoolvally answer:

They want to find out the effect of change in orientation of plant. how the stem and roots grow or behave in different positions.  

9. Design an experiment to check if  temperature has an effect on seed  germination.

Schoolvally answer:

Take some seeds like kidney beans or chick pick and divide them in three parts in  three dishes.

Keep one dish in freezer of refrigerator.

Keep second dish in refrigerator.

Keep third dish at room temperature away from sunlight.

Check them every day and note the changes.

After one week you will observe that :

(a) There is no germination in the seeds kept in freezer of refrigerator. 

(b) Stage one germination in seeds kept in refrigerator.

(c) long sprouts in the third dish kept in room temperature.

This experiment shows the effect of temperature on germination of seeds.

 Can we grow plants without germinating their seeds?  Explore and cite some examples. 

Schoolvally answer:

We can grow plants by sowing stem of the pant in soil, this is called vegetative propagation.

 Try to observe some of the stages in the life cycle of a  butterfly or a moth. Are these stages similar to the stages in  the life cycle of a mosquito?  

Schoolvally answer:

The life cycle of both butterflies and mosquitoes includes distinct stages of development but differs in specific details. Both insects undergo complete metamorphosis, involving four main stages: egg, larva (caterpillar or mosquito larva), pupa (chrysalis or mosquito pupa), and adult. Butterflies start as eggs that hatch into caterpillars, then transform into chrysalises before becoming adult butterflies. Mosquitoes, on the other hand, hatch into larvae that live in water, pupate into mosquito pupae, and emerge as adult mosquitoes. Although the stages are similar in their basic structure, the forms and habitats of the larval and pupal stages vary between these two groups of insects.

 Add more lines to the incomplete poem given below. Include  information on the different stages in development of a  frog. You may also draw and paint each stage as it appears  in your poem. 

 Schoolvally answer:

In shaded and grassy bogs,
There lived a group of frogs.
They happily sang from dusk to dawn,
In double bass going on and on.

One day sitting beside a reed,
Female frogs think it’s time to breed.
Eggs they lay in clusters tight,
In the cool, calm waters, a shimmering sight.

Soon the eggs hatch, and out come the tadpoles,
Wriggling about with their tiny tails and roles.
They swim and munch on algae, so small,
Growing in size, their tails like a ball.

As weeks go by, they start to change,
Legs begin to sprout, it’s quite strange.
Their tails shorten, and they lose their gills,
Breathing air now, and catching flies with skills.

Finally, as a froglet, they leap and bound,
From water to land, they are now unbound.
They grow into frogs, with a jump and a croak,
In grassy bogs, where their songs invoke.

In shaded and grassy bogs,
There lived a group of frogs.
From eggs to tadpoles to frogs full grown,
In the wetlands’ melody, their lives are shown.

EQ 1. Define living?

Schoolvally answer:

 The essential features of living beings are that they move,  eat, grow, breathe, excrete, respond to stimuli, reproduce  and die. Absence of any of these features indicates that they  are not living beings. 

EQ 2. Difference between living and Non-living?

Schoolvally answer:

Living Things:

1. Growth: Living things grow over time. For example, a seed grows into a plant.

2. Movement: Living things move from one place to another or move their body parts. For example, animals walk, and plants turn toward the light.

3. Reproduction: Living things can reproduce, they produce new ones of one’s own kind meaning they can create offspring or new individuals like themselves. For example, animals have babies, and plants produce seeds.

4. Respiration: Living things need air or oxygen to breathe in. For example, humans and animals breathe in oxygen.

5. Respond to stimuli: Living things can respond to their environment. For example, plants can bend towards the sun,  Mimosa Pudika fold their leaves when you touch them and animals react to sounds or smells.

6. Excretion: Living things get rid of waste form their body. For example, animals sweat or urinate, and plants drop dead leaves and bark. Also expel out gases from their leaves.

7 .  Nutrition  : living things  eat their food and need water to drink.

Example: Plants, animals, humans, insects

Non-Living Things:

1. No Growth: Non-living things do not grow. For example, a pencil or a book remains the same size.

2. No Movement: Non-living things do not move on their own. For example, a chair stays in place unless someone moves it.

3. No Reproduction: Non-living things do not reproduce. For example, a table doesn’t create new tables.

4. No Respiration: Non-living things do not need air or oxygen to breathe in. For example, a computer doesn’t breathe.

5. Respond to stimuli: Non-living things do not respond to their environment. For example, a cup doesn’t react to the temperature of the room.

6. No Excretion: Non-living things don’t produce waste. For example, a pencil doesn’t get rid of any waste.

7 . No Nutrition  Non-living things do not eat any food or drink water.

Example: Rocks, water, toys, furniture

EQ 3. Define dead?

Schoolvally answer:

 When a living being is not able to exhibit characteristics like nutrition intake, growth, respiration, reproduction, respond to stimuli, excretion or waste, despite the availability of all  resources (like food, stimulus, air and water) needed for being alive, it is said to be dead. So, in other words we can say that a dead is like a nonliving thing.

EQ 4. What is germination and condition of germination?

Schoolvally answer:

 When a seed turns into a sprout, it is said to have  germinated. Essential  conditions for seed germination are presence of – air, water and sunlight.

 Water: Seeds require water for germination.  Water enables the seeds to carry out the  processes necessary for their growth. 

The outer  covering of the seed is called seed coat. Water  softens the seed coat and helps the tiny embryo  inside it to develop into a plant.

 Air and Soil: Seeds need air for germination. They use the  air available in the spaces between soil particles. Moreover,  spaces between the soil particles allow roots to grow easily. 

Light and/or dark conditions: Most seeds do not require light for  germination. But after germination, sunlight is required for  further growth of the seedling.

EQ 5. Give example of seeds that need light to germinate and those which do not need light for germination?

Schoolvally answer:

 Some seeds of flowering plants, like Coleus and  Petunia, require light to germinate. Covering  these seeds with soil inhibits their sprouting.  

Seeds of flowering plants, like Calendula and  Zinnia, need darkness to germinate. These seeds  should be covered with sufficient soil. 

EQ 5. How do plants respond to sunlight?  

Schoolvally answer:

Shoots of plants grow upward and exhibit movement towards  sunlight (negatively geotropic) but roots of plants grow downwards.(positively geotropic) 

EQ 6. Life cycle of bean plant?

Schoolvally answer:

 A seed grows into a young plant and matures to produce  flowers and fruit. The fruit, in this case a pod, contains  seeds which give rise to a new generation of bean plants.  The entire process from a seed to a plant, and then, to the  next generation of seeds is called the life cycle of a plant . When a plant stops growing and all activities of  life gradually comes to an end, even after the availability of  all the necessary conditions, the plant is considered dead. 

Note: complement this answer with  Fig. 10.4: Life cycle of a bean plant given on your test book for better marks.

EQ 7. Life cycle of mosquito?

Schoolvally answer:

Mosquitoes undergo a four-stage life cycle: egg, larva, pupa, and adult. Initially, the mosquito starts as an egg, which develops into a larva. The larva then transforms into a pupa, and finally, the pupa becomes an adult mosquito. After emerging from the pupa, the adult mosquito rests briefly on the water's surface before flying away. 

An adult mosquito typically lives for 10 to 15 days. Significant changes in appearance and structure occur at each stage, making the transformation from one stage to the next quite distinct and sometimes surprising. 

The adult female lays eggs near water, this continues the life cycle of cycle.

Note: complement this answer with  Fig. 10.6: Life cycle of a bean plant given on your test book for better marks.

EQ 8.Life cycle of Silk worm?

Schoolvally answer:

 The silk moth passes through four life stages—egg, larva,  pupa and adult. Eggs hatch into larvae, which then grow in  size. Larvae secrete thread-like material which they  wrap around themselves, before changing to pupae.  These are the fibres that are used to make silk fabric. 

EQ 9. What is spawn?

Schoolvally answer:

Spawn  consists of clusters of frog eggs.

It is white jelly-like substance found on the surface of a pond or attached to aquatic plants is frog spawn. 

EQ 10.What are different stages, in the life cycle of Frog?

Schoolvally answer:

 Generally, the sequence starts with the earliest developmental stage and progresses through to the adult frog. The stages typically include:

1. Stage A: Spawn (eggs) - The initial stage where the frog begins its life.
2. Stage B: Embryo - The early development within the egg.
3. Stage C: Tadpole with tail - A stage where the tadpole has a tail but no legs.
4. Stage D: Tadpole with legs - Tadpoles develop hind legs while retaining their tails. at this stage with hind legs; this is called the froglet stage.
5. Stage E: Froglet - An intermediate stage resembling a small frog, with developed legs and a reduced tail.
6. Stage F: Adult frog - The final stage, where the frog is fully developed and capable of living both in water and on land the life cycle of a frog.

  1. Fig. 11.9 shows items related to natural resources. Match  them with their jumbled up names. Make another table and  write the names of these resources. Classify these resources  as renewable or non-renewable. 

Schoolvally answer:

(a) Water

(b) Wind

(c) Forest

(d) Rock

 2. State whether the following statements are True [T] or  False [F]. If False, correct them.  

Schoolvally answer:

(i) Nature has all the resources to meet human needs. [ True ] 

(ii) Machines are a resource found in nature. [ False ] 

(iii) Natural gas is a non-renewable resource. [ True ] 

(iv) Air is a renewable resource. [ True ] 

 3. Fill in the blanks using the most appropriate option— 

(i) A fuel that is commonly used in two wheelers like  scooters or bikes is......... 

(a) Kerosene  

(b) Petrol   

(c) Diesel   

(d) LPG  

Schoolvally answer:

 (b) Petrol 

(ii) An example of a renewable resource is ..................   

(a) Coal   

(b) Water  

(c) Natural gas  

(d) Petrol  

Schoolvally answer:

( b) Water 

4. Classify the following as renewable or non-renewable  resources—coal, natural gas, forests and minerals. 

Schoolvally answer

renewable: 

forests

non-renewable : 

coal, natural gas and minerals.  

5. Why do we say that petroleum is a non-renewable resource?  

Schoolvally answer:

We say so, because it takes millions of years to form petroleum. They are formed essentially from the  remains of microorganisms and plants that got buried deep inside the earth, and were converted to petroleum, natural  gas and coal.

6. It is difficult to regrow forests. Justify this statement.  

Schoolvally answer:

Regrowing forests is challenging because it requires restoring entire ecosystems, not just planting trees. This involves rebuilding soil quality, reintroducing various species, and addressing environmental changes. Factors like deforestation, soil damage, and climate shifts make the process slow and complex.

7. Make a list of five daily activities in which you use natural  resources. Suggest ways by which you can reduce their use. 

Schoolvally answer: 

Five daily activities in which we use natural resources:

Natural resource water is used in many ways:

1.  Watering plants and vegetables

2. . Activities such as drinking,  cooking, bathing, washing and cleaning

3. For  industrial purposes.

Natural resource air is used in many ways: 

1. Air is used for breathing.

2. Moving air 'wind' is used to run wind mills.

3. To maintain air pressure in automobile tyre.

Natural resource mineral is used in many ways: 

1. Minerals in the form of rocs are use in construction.

2. Gold a type of mineral is used as jewelry.

3. Iron a type of mineral is used to form tools.

8. List four activities that are possible due to the presence  of air. 

Schoolvally answer:

Activities that are possible due to the presence air are as under:

1. Air is used for breathing.

2. Moving air 'wind' is used to rotate the wings of windmill and run run flour mill.

3. To maintain air pressure in automobile tyre.

4. Gilding and flying airplane is possible, due to air.

9. How can you contribute towards enhancing the green cover of your locality? Make a list of actions to be taken. 

Schoolvally answer:

 Qver the years, the forest cover has  been decreasing, mainly due to human activities like large scale cutting of trees. It takes many years to grow a new  forest or restore lost forests. Therefore, we must preserve  and use forests responsibly so that they get enough time  to regenerate. 

For this we can plan activities like, Van Mahotsav in our area. Van Mohotsav is a forest festival  during which new plants  and trees are planted and  awareness about respecting  forests is raised in community. The aim of the event is to increase the green  cover. 

 10. In the given illustration, we see that food is  being cooked.  Answer the following questions— 

(i) What type of energy is being  used for cooking? 

Schoolvally answer:

 Solar energy

(ii) Name one benefit  and one drawback  of using this type of  energy for cooking. 

solar energy is renewable source of energy, so it will never 

Schoolvally answer:

This sis a renewable source of energy, It is available in abundance It is free and clean fuel. 

The drawback is that it is not available near poles of earth. In other regions it is available for limited hours of day only.

11. Cutting down trees on a large  scale impacts the quality of the soil. Why do you think it is so?

Schoolvally answer: 

Yes, this statement is true, because the roots of the tree hold the soil and save it from erosion. The top soil is most fertile and important.

 Forests help to bring rain on earth as they have a vast surface area for water to evaporate into the air through transpiration. Thus, this water vapour rises into the air, condenses into clouds and finally precipitates and falls on earth as rain. Water attracts birds and animals and maintains ecosystem.

12. Explain two ways in which human activities pollute the air.  Propose one action which can help in reducing air pollution. 

Schoolvally answer:

(a) Human use fossil fuels as source of energy for cooking and running vehicles this causes air pollution.

(b) Industries and factories produces poisonous gases that causes air pollution.

there are some steps that we should take to control pollution like:

(a) Walking or cycling to nearby places. (b) Using public transport. 

(c) Using alternative to fossil fuels like solar energy, hydro energy and wind energy.

13. A family uses solar panels to generate electricity, a gas stove  to cook food and a windmill for pumping water from a well.  What would happen if there were no sunlight for a week? 

Schoolvally answer: 

If there is no sunlight for a week their only electrical appliances will not work.  Their life activities will be hindered a little as they are not 100 percent dependent on solar energy for their daily power/energy dependence.

14.  Fill up the blanks using the following terms—  (fossil fuels, forest, air, petroleum, coal, water and non renewable resource) 

Schoolvally answer:

(a) Non renewable source of energy.> Fossil fuels>> Petroleum, Natural gas, Coal.

(b) Renewable sources> Air, Water, Forest. 

15. There is an increasing demand of trees to meet the  requirements of industries and for housing. Therefore, trees  are being felled. Is it justified? Discuss and prepare a brief  report. 

Schoolvally answer:

The increasing demand for trees to meet the requirements of industries and housing has led to extensive deforestation this is serious concern. While this may provide immediate economic benefits to a few, it is not justified due to the severe long-term consequences it poses for the environment and future generations. 

It takes years for a tree to grow and form forests, Forests are back bone of ecosystem. Birds and animals find shelter in them and keep them in growing with their activities.

If there are no trees,

there are no forests,

If there are no forests,

there is no place for humans too.

We should turn to eco friendly alternatives and save our environment

16. Propose a plan to use less water in your school. What steps  would you take to make this plan happen and how would it  help the environment? 

Schoolvally answer:

Below is the plan to Use Less Water in School-

1. Installation of Efficient Fixtures: Replace old faucets, toilets, and showerheads with low-flow or water-efficient models.

2. Implementation of Water Saving Practices: Educate students and staff on turning off taps while washing hands and using water sparingly.

3. Regular Maintenance and checking: 

Conduct routine checks for leaks and repair them promptly to prevent water wastage.

4. Choosing the plants for garden: 

Use drought-resistant plants and plants that need less water.

5. Wise and efficient usage:  Students may bring their own water bottles and use left over water to irrigate garden.

7. Rain water harvesting is a good method to collect and store water.  This will decrease dependence on municipal water.

Benefits to the Environment could be summarised as under:

 These steps would significantly reduce water consumption, decrease the strain on local water supplies, and contribute to energy savings by lowering the need for water treatment and distribution. This helps preserve natural resources and supports overall environmental sustainability.

  Rainwater harvesting is an age-old practice in India. Find  out some of the traditional rainwater harvesting techniques  being used in your state or in other parts of the country. 

Schoolvally answer:

 Some traditional techniques is,  Stepwell,  commonly known as Bawadi in  Rajasthan and Vav in Gujarat are  built for water harvesting as a  response to the scarcity of water in  these regions. These stepwells have  a unique system of water harvesting.  

They store not only rainwater but  also water seeping from nearby  lakes, ponds and rivers. The walls of  the trenches (long deep holes dug in  the ground) are lined with blocks of  stones that allow seepage of water. 

 Investigate the effect of air pollution on human health by  interacting with your elders or community members and  identify the main sources of air pollution in your local area.  Based on your findings, suggest two practical steps that your  school or community could take to help reduce air pollution. 

Schoolvally answer:

Air polution has severe effect on health of humans. It causes diseases like bronchitis and asthma.

Air pollution causes emotional disbalance and makes one irritable.

The main source of air pollution in my area is-

- Large number of Vehicles on the road and lanes.

Two suggestive steps could be:

(a) Car pooling is a good idea to reduce the strength of vehicles on the road.

(b) Online classes for twice a week will help to reduce the school trips.

  Prepare a list of the names and uses of important  minerals and rocks that are used in your village/town/city  for various purposes. 

Schoolvally answer:

(a) Marble is used in construction industry for flooring and to make handicrafts.

(b) Mica is used in cosmetic industry.

 You are an eco-club monitor. Organise a tree plantation  drive in your school with the help of your teacher. List  the steps required for organising this activity. Prepare a  one-page report listing the names of the trees planted along  with their importance.

Schoolvally answer: 

In the month of July when Van Mohotsav is celebrated nation wide, we will organized a Plant festival.

The activity is to be carried in 4 steps in 2 days.

Day One:

Step 1: Red House volunteers will do the marking where plant is to be sown.

Step 2: Green house will do the digging of pits.

Day two:

Step 3: Yellow house volunteer will put the pants and fix them firmly.

Step 4: Blue house volunteer will water the plants.

Teachers will monitor the activity and maintain the discipline.

EQ 1. Define rainwater  harvesting?

Schoolvally answer:

  Water harvesting is one of the  methods for conserving water. In many  buildings, rainwater is collected  and stored in large quantities for  later use. This is called rainwater  harvesting.

 For example, stepwells commonly known as 'Bawadi' or 'Bowli' in  Rajasthan and Vav in Gujarat are  built for water harvesting as a  response to the scarcity of water in  these regions.   

EQ 2. What is van Mahotsav?

Schoolvally answer:

 Van Mahotsav is a week long event celebrated across  the country during the month  of July. It is a forest festival  during which new plants  and trees are planted, and  awareness about respecting  forests is raised. The aim of the  event is to increase the green  cover.

EQ 3. Define Fossil fuels?

Schoolvally answer:

 Petroleum along with natural gas and coal are commonly  called fossil fuels. They are formed essentially from the  remains of microorganisms and plants that got buried deep  inside the earth, and were converted to petroleum, natural  gas and coal. It takes millions of years for these fuels to form.

EQ 4. Define natural resources?

Schoolvally Answer: 

 These resources which we  get from nature are called natural resources.

 They are essential  resources to sustain all life forms on the Earth. For example,  we get heat and light from the Sun, water from rivers, and  food from plants and animals. 

EQ 5. Define human made resources?  

Schoolvally answer:

 Resources created by human beings are called human made resources.  For example, electric bulbs, furniture, solar  panels, bicycles, etc., make our lives comfortable.  

EQ 6. Define Renewable sources of energy?

Schoolvally answer:

 Resources which get renewed, replenished  or restored within a reasonable period of time are called  renewable resources. Air, water and forest are some of the  examples of renewable natural resources. Nature renews  them. 

EQ 7. Define  non-renewable resources of energy?

Schoolvally answer:

 Resources which do not get renewed, replenished  or restored with reasonable period of time. In other words,  resources that are in limited quantities and do not  get replenished within a reasonable period of time are called  non-renewable resources Since they are found in limited quantities and once used,  they get exhausted. They are not produced or replenished  within a reasonable period of time. These resources are called  non-renewable resources. 

Examples of non-renewable natural resources are minerals, soil, rocks, coal, petroleum  and natural gas. All the fossil fuels are non renewable resources they take millions of years to form.

1. Match the column:

Schoolvally answer:

 Column I   -------   Column II  

(i) Satellite of Earth  -----  (d) Moon  

(ii) Red planet    -----   (c) Mars 

(iii) Constellation  ----- (a) Orion 

(iv) Planet which is commonly  called an evening star -------- (b) Venus

 2. (i) Solve the following riddle. 

My first alphabet is in MAN but not in CAN 

My second alphabet is in ACE and also in FAN  

My third alphabet is in RAT and not in CAT 

My fourth alphabet is in SUN but not in FUN 

I am a planet that moves around the Sun.   

Schoolvally answer:

MARS

(ii) Make two similar riddles by yourself. 

Schoolvally answer: 

Riddle 1

My first alphabet is in EGG but not in BLOG. 

My second alphabet is in ANGEL and not in NGEL. 

My third alphabet is in RACE but not in ACE. 

My fourth alphabet is in TANGO but not in ANGLO. 

My fifth alphabet is in HAT but not in CAT. 

I am a planet that moves around the your Sun.

Solution: EARTH

Riddle 2

My first alphabet is in BRIGHT you are RIGHT.

My second alphabet is in LOOM and not in OOM. 

My third alphabet is in UP but why dis you SIT.

My fourth alphabet is twice in EEL did you get ant COLOUR feel. 

I am a YOUR planet also known as _ _ _ _ Planet.

Solution: Blue planet- (Earth)

3. Which of the following is not a member of our Solar System?  

(i) Sirius 

(ii) Comets 

(iii) Asteroids  

(iv) Pluto 

Schoolvally answer:

(i) Sirius 

Column I ---- Column II  

(i) Satellite of Earth  ---- (d) Moon 

(ii) Red planet    ------  (c) Mars  

(iii) Constellation   ----- (a) Orion 

(iv) Planet which is commonly  called an evening star   ----- (b) Venus 

 4. Which of the following is not a planet of the Sun?  

(i) Jupiter 

(ii) Pluto 

(iii) Neptune  

(iv) Saturn 

Schoolvally answer:

(ii) Pluto

5. Which is the brighter star, the Pole Star or Sirius?

Schoolvally answer:

 Sirius is the brightest star in the night sky. Its name is derived from the Greek word 'Seirios', meaning 'glowing' or 'scorching'.  

6. An artist’s representation of the Solar System is given in Fig. 12.12. Is the order of the planets correct? If not, write the  correct order in the boxes in the figure. 

Schoolvally answer:

The correct sequence be:

 Sun.  Mercury, Venus, Earth, Mars, Jupiter, Asteroid Belt, Saturn. Uranus, Neptune.

 7. A portion of night  sky with stars is shown in Fig. 12.13.  Look carefully and  identify the groups  of stars that form  the patterns—the  Big Dipper and the  Little Dipper. Draw  lines to connect  the stars for these  patterns and label  them. Also, identify  and label the Pole  Star. You may refer  to Fig. 12.4 for help.

Schoolvally answer:

Sketch 

 8. A portion of the night sky is shown in Fig. 12.14. Draw lines to connect the stars for Orion and label the star Sirius. You  may refer to Fig. 12.3.

Schoolvally answer:

Sketch

 9. You can see stars fading away at dawn and appearing at  dusk. During the day we do not see the stars. Explain why.   

Schoolvally answer:

 During the day, the Sun's light is so bright so it over shadows the light of little stars, which other wise are there only  Thus, they are not visible during the day. 

10. During a clear night, try to observe the Big Dipper 3–4  times at an interval of 2 to 3 hours. Also try to locate the Pole Star each time. Does the Big Dipper appear to move?  Draw a rough sketch to illustrate this, mentioning the time  in each case. 

Schoolvally answer:

 Each time, it seem as if the North Star (Polaris) remains in the center, while the Big Dipper moves around it in a counter clockwise direction due to the Earth's rotation. 

This movement is why the Big Dipper appears to change its position in the sky over the course of the night. 8.00pm,9.00pm, 11.00pm and 01.am

Note in this Activity:

Key Points

• Polaris: Polaris remains relatively fixed in the sky because it is located near the axis of Earth’s rotation. It serves as a reference point for the rotation of other stars and constellations.
• Movement Pattern: The Big Dipper's movement is circular around Polaris. This movement is continuous, so the pattern you observe will be consistent with the rotation of the Earth.

In summary, if you observe the Big Dipper at different times throughout the night, you will indeed see it move around Polaris due to the Earth's rotation. 

11. Think about the night sky and write a poem or a story on it. 

Schoolvally answer: 

Title: -A Night Under the Stars

When the sun dips low,

and the sky turns deep blue,  

The stars peep out, 

each one as a bright little clue.  

The moon starts to shine,

 with a silvery glow,  

And the night sky is painted,

 with a magical show.

Look up and you’ll see,

the Big Dipper's spoon,  

the seven stars twinkle mildly, 

like diamonds in a crew.

It spins in the sky, 

dancing round and round,  

While the North Star, Polaris, 

stays fixed and makes no sound.

The night is a canvas,

where stars happily play,  

Each constellation has a story,

 to tell in its own way.  

They shimmer and sparkle, 

so high and so bright,  

Guiding our caravan,

through the, alone night.

As hours slip by

and the sky starts to shift,  

They gather their sparkle,

to get ready for next shift.

The stars in their places, 

like a grand, endless sea,  

Whispering secrets to them,

who pray and plea.

So next time you gaze,

at the sky’s dark embrace,  

Remember the place of each star,

and how they grace.

The night sky’s no wonder, 

a magical sight,  

With the stars and the moon,

beautiful thoughts for night.

Hey! read my others Poems in My Rachna Blog.

Try to find out the names of planets in your local language.  Also, find out the stories associated with stars and  constellations in your region. Present these stories in a  pictorial form.  

Schoolvally answer:

Planet and their names in Hindi:

1. Mercury - बुध (Budh)
2. Venus - शुक्र (Shukra)
3. Earth - पृथ्वी (Prithvi)
4. Mars - मंगल (Mangal)
5. Jupiter - बृहस्पति (Brihaspati)
6. Saturn - शनि (Shani)
7. Uranus - अरुण (Arun)
8. Neptune - वरुण (Varun)
9. Pluto - प्लूटो (Pluto) 

Story-  Saptarishi Mandal - The Seven Sages

The Saptarishi Mandal, or the Big Dipper, is associated with the seven great sages (Saptarishis) of Hindu mythology. According to the legend, these sages are revered for their wisdom and are said to be constantly observing the universe from their celestial positions.

Story- Dhruva Tara) - The Pole Star

The Pole Star (Polaris) is known as Dhruva Tara in Hindi, and it is associated with the story of Dhruva, a young prince who performed penance to attain a permanent place in the sky. His unwavering devotion and determination earned him a spot as a star in the northern sky.

 Find out if the increasing light pollution is  causing problems for humans, wildlife and the  environment. Write an action that you would  take at the personal level to control light  pollution. 

Schoolvally answer:

Increasing light pollution is having significant impacts on humans, wildlife, and the environment equally. 

For humans, it disrupts natural sleep patterns and can lead to various health problems. 

Artificial lights can disrupt animals' behaviors, such as nesting and migration.

It can  confuse nocturnal (animals that hunt in night) animals. 

Light pollution spoils our ability to view and study the night sky which is a great hobby and life style pattern of many. 

  To control light pollution personally, one effective action could be to minimize the use of outdoor lighting.

Opt for motion-sensor lights or install dimmable fixtures to reduce unnecessary light. 

Ensure that street lights are directed downward correctly and are are switched on only when required.

These simple steps can contribute to reducing light pollution and help maintain a healthier balance for both humans and wildlife.

Find out the weather conditions due to which  the Indian Institute of Astrophysics (IIA) found  Hanle, Ladakh a suitable place to set up an  observatory. 

Schoolvally answer:

The team discovered that the Hanle site is as arid as the Atacama Desert in Chile, significantly drier than Devasthal. It enjoys approximately 270 clear nights annually and is emerging as a prominent location for infrared and sub-mm optical astronomy.

EQ 1. Define constellations.

Schoolvally answer:

 The sky is divided into regions called constellations, which  include groups of stars that appear to form patterns. 

Internationally agreed  set of constellation boundaries were defined by the  International Astronomical Union (IAU).

Example of some of the constellations are- 

(a) The constellation Orion is often represented as a hunter.  Constellation (b) Canis Major often represented as dog.

(c) Constellation Taurus represented as bull.

(d) Ursa major often represented as greater bear.

EQ 2. Name the brightest star in the night sky.

Schoolvally answer:

The name of brightest star is 'Sirius' it is  present in the constellation 'Canis Major'.

EQ 3. What is saptrishi?

Schoolvally answer:

 In India the  Big Dipper is known  as 'Saptaṛiṣhi', and the  Pole Star is known as  'Dhruva tārā'. There are many tales associated with constellations in different countries and religions. 

EQ 4. What is big dipper and little dipper? 

Schoolvally answer:

 The 'Big Dipper' and 'Little dipper' are two distinct patterns of stars which lies in the constellation Ursa Major and Ursa Minnor respectively. 

The Pole Star or Polaris, is part of the Little Dipper. The Pole Star appears stationary in the North direction,  which helps to locate the North direction in the Northern  hemisphere. 

EQ 5. What is Light pollution?

Schoolvally answer:

 The  presence of excessive artificial light at night time is referred  to as light pollution.

 Light pollution is growing sharply

 globally. This is reducing our  ability to enjoy and study objects in the night sky. Some  dark sky reserves and parks have been established  around the world.  

EQ 6. Is Pole star visible from the southern hemi sphere?

Schoolvally answer:

No, Pole Star is not visible from  the southern hemisphere of Earth, because earths own curvature prevents it. It lies in line with the north pole. Pole star lies exactly above overhead if seen from north pole of the earth.

EQ 7. Name the closest star?

Schoolvally answer:

 The Sun is the closest star to us. It is an extremely hot spherical ball of gases. The Sun gives out a huge  amount of energy, and that is why it glows so brightly.  

The Sun produces heat and  light, and is the main source  of energy on the Earth. 

EQ 8. How big is the Sun?

Schoolvally answer:

The Sun is about 100 times bigger than  the Earth in diameter.

It looks so small because it is very far from the Earth.

EQ 9. Devine Astronomical Unit?

Schoolvally answer:

A useful unit for expressing distances within the  solar system is called ‘astronomical unit’ (au) .

Astronomical unit is approximately the distance between the Sun and  the Earth.

 The distance of the Sun from the Earth is about 150 million  km. Hence we can say that:

1au =  150 million kilometers or 93 million miles or 8 light years.

EQ 10. Name the nearest star?

Schoolvally answer:

 The star nearest to us after the Sun is Proxima  Centauri which lies at a distance of about  269000 au. 

This means that its distance is about  269000 times our distance to the Sun.

EQ 11. Define  revolution ? 

Schoolvally answer:

 The  movement of an object around  the Sun is called revolution. 

In simple words  Revolution refers to the movement of a planet around the Sun or another star. 

This determines the length of a planet's year. The planet's orbit around the Sun defines how long it takes to complete one full orbit.  

 Example: Earth takes about 365.25 days to complete one revolution around the Sun, which defines the length of a year. 

EQ 12. Define rotation?

Schoolvally answer:

 While revolving around the Sun, the Earth is also  rotating about its axis. For one full rotation, the  

In other words,  rotation refers to the spinning of a planet around its own axis.   

This is what causes day and night on a planet. 

A planet's rotation determines the length of its day. 

 Example: Earth rotates once every 24 hours, which is why we experience day and night on a 24-hour cycle. So we can say that earth takes about 24 hours which is called a day. 

EQ 12. Define Planet and dwarf planet?

Schoolvally answer:

 A planet is a large, nearly spherical object that revolves  around the Sun. Our Earth is a planet as it revolves around  the Sun. The Earth takes nearly one year to complete one revolution. Like the Earth, there are  other planets that revolve around the Sun.

  list of the planets in our Solar System, ordered by their distance from the Sun are as below:

1. Mercury: The closest planet to the Sun.
2. Venus: The second planet from the Sun.
3. Earth: Our home planet, the third from the Sun.
4. Mars: The fourth planet from the Sun.
5. Jupiter: The fifth planet from the Sun and the largest in the Solar System.
6. Saturn: The sixth planet from the Sun, known for its prominent ring system.
7. Uranus: The seventh planet from the Sun, an ice giant with a unique tilt.
8. Neptune: The eighth planet from the Sun, another ice giant known for its deep blue color.

EQ 13. Define Dwarf planet?

Schoolvally Answer: 

A dwarf planet is a celestial body that -orbits the sun, has enough mass to assume a nearly round shape, has not cleared the neighborhood around its orbit and is not a moon.

 List of dwarfs is as under:  Pluto, Eris, Haumea, Makemake, and Ceres, which are part of our Solar System but do not fit the criteria for being classified as full-fledged planets.

EQ 14. Define Inner planets?

Schoolvally Answer:

 The inner four planets nearest to the Sun—Mercury,  Venus, Earth and Mars—are smaller in size. They have solid  surfaces with rocks on them.  

EQ 15. Define outer planets?

Schoolvally Answer:

 The four outermost planets—Jupiter, Saturn, Uranus and  Neptune—are much larger compared to the Earth, and are  mostly made of gases. These giant gaseous planets have  large flat ring-like structures around them which are made  of dust particles and rocky material. 

E1 16. Which planet is called Red planet?

Schoolvally answer:

 Mars is called the Red Planet  because it appears red. This is because the soil on Mars is  reddish in colour 

EQ 17. Which planet is called morning star?

Schoolvally Answer:

 Venus is usually seen shining brightly at dawn and dusk,  and is commonly called the Morning Star or the Evening  Star, even though it is not a star.

EQ 18. Which planet is called blue planet?

Schoolvally Answer:

 A large portion of the Earth’s surface is covered with  water and thus, it appears blue from the space. Due to this,  the Earth is also called the Blue Planet. 

EQ 19. Why is Venus hotter than Mercury? 

Schoolvally Answer:

Planets get most of their energy from the Sun. So,  the  farther they are, the colder they are in general. The  presence of an atmosphere on a planet can trap heat which  can significantly change the temperature of a planet. That is  why Venus, for example, is hotter than Mercury, although it  is farther from the Sun. 

EQ 20. Which is the  brightest planet of our solar system?

Schoolvally answer:

 Among the planets, it is  easiest to identify Venus  which is very bright. After  the Sun and the Moon, Venus  is the brightest object in the  sky. 

EQ 21. Which planet can you see with naked eye?

Schoolvally answer:

  Mercury, Mars, Jupiter  and Saturn can also be seen  with the naked eye. They are  Chapter 12.indd 242 10-07-2024 18:17:01 Beyond Earth 243 so far away that they look like shining dots.

EQ 22.  how can we distinguish between planets and the stars? 

Schoolvally answer:

 Unlike planets, the stars appear to twinkle a lot.  

EQ 23. What is telescope?

Schoolvally answer: 

 A telescope is an optical instrument designed to observe distant objects by gathering and magnifying light.  A telescope also helps us  view many dim objects not visible by our naked eyes  directly. 

Learn how to make your own DIY telescope.

 While many of the objects in the sky can be seen  with our naked eyes directly, we can see them brighter and larger using a pair of binoculars or an instrument  called a telescope. A telescope also helps us  view many dim objects not visible by our naked eyes  directly. 

EQ 24. What do you mean by satellite?

Schoolvally answer:

 Objects that move around planets are commonly called  satellites. They are smaller in size than planets. 

Moons are  natural satellites of planets. The Earth has one Moon, while  Mars has two moons or satellite. Jupiter, Saturn, Uranus and Neptune  have a large number of satellites. 

EQ 25. What is Moon?

Schoolvally answer:

The Moon, is the only natural satellite that orbits earth. Natural satellite means    a celestial bodies that is formed naturally in space. 

Moon takes approximately 27 days to orbit Earth and is our closest celestial neighbor. 

It is about a quarter ( 1/4 ) of Earth's diameter. The Moon has a very thin atmosphere and no water which means It cannot support any life. 

 The Moon’s  surface shows circular bowl-like  structures called craters. Most of these craters have  been formed due to the impact of asteroids or rocks from the space  hitting the Moon’s surface Despite its distance, spacecraft have been sent to explore the Moon, including India's Chandrayaan missions, with more missions planned for the future.

EQ 30. What are Asteroids and Asteroid  belt?

Schoolvally answer:

 There  are many small objects in the Solar System which are rocky  and irregular in shape. These are called asteroids. 

Many of  these asteroids revolve around the Sun  in paths that lie between those of Mars  and Jupiter. This region is called the  asteroid belt. Occasionally, asteroids pass very close to the Earth.

EQ 27. What are comets?

Schoolvally answer: 

A comet is a small celestial body that orbits the Sun and is made of ice, dust, and rocky material. When a comet gets close to the Sun,  As a comet approaches close to the Sun,  the frozen material in it starts evaporating. This evaporating material forms the tail of comet. Comets appear dim as  they move away from the Sun and then, it is not possible to  see them with the naked eye. 

 Many comets have been  found that revolve around  the Sun. These comets  approach close to the Sun  periodically. However, there  are a few comets that escape  and move out of the Solar  System. Few other comets  get broken up, or fall into the  Sun or other planets when  they approach them.  

EQ 28. What is  solar system?

Schoolvally answer:

 The Sun, eight planets, their  moons, and many smaller  objects including asteroids,  and comets, together form the  Solar System. 

The Sun our star is in the central position and is the largest and the heaviest object  in the Solar System. 

The Sun  produces almost all the energy in  the Solar System. All other objects  in our Solar System shine due to  the sunlight that they reflect from  their surfaces.

EQ 29. What is milky way galaxy?

Schoolvally answer:

Milky way is our home galaxy also known as Akash Ganga.

The Milky Way is a spiral galaxy that contains our Solar System and is one of billions of galaxies in the universe.

With naked eye, we can see an extended faint band of light from near north to south across the sky.

 A galaxy has millions to billions of stars. Our Solar  System is part of the Milky Way Galaxy.

EQ 30. What do you mean by 'The Universe' ?

Schoolvally Answer: 

 The universe is everything, including space, time, matter and energy. 

The universe is the vast and ever expanding, that includes everything that exists: all matter, energy, planets, stars, galaxies, and the cosmic structures between them. 

Its contents are governed by physical laws. The universe began with the Big Bang approximately 13.8 billion years ago and is continually expanding.