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Home Explore 212210041-COMPASS-STUDENT-TEXTBOOK-SCIENCE-G03-PART2

212210041-COMPASS-STUDENT-TEXTBOOK-SCIENCE-G03-PART2

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CO MPASS SERIES science textbook part - 2 3 Name: [email protected] Sec�on: Roll No.: School:



Preface ClassKlap partners with schools, supporting them with learning materials and processes that are all crafted to work together as an interconnected system to drive learning. Our books strive to ensure inclusiveness in terms of gender and diversity in representation, catering to the heterogeneous Indian classroom. ClassKlap presents the Traveller series, designed specifically to meet the requirements of the new curriculum released in November 2016 by the Council for the Indian School Certificate Examinations (CISCE). Guiding principles: The 2016 CISCE curriculum states the following as its guiding principles for Science:  Theme-based learning  Relating science learning to the daily-life experiences of students  Focus on skill/process development  Providing opportunities for knowledge construction  Infusion of environmental issues into the content Each of these principles resonates with the spirit in which the ClassKlap textbooks, workbooks and teacher companion books have been designed. The ClassKlap team of pedagogy experts has carried out an intensive mapping exercise to create a framework based on the CISCE curriculum document. Key features of ClassKlap Traveller series:  Theme-based content that holistically addresses all the learning outcomes specified by CISCE curriculum  Opportunities for experimentation, analysis and synthesis of ideas and concepts  Exposure to locally relevant environmental problem solving  Focus on science-specific vocabulary building  Promotion of participatory and contextualised learning through the engagement of all relevant stakeholders in the learning process All in all, the Traveller Science books aim to enhance the learning of science, development of scientific temper and curiosity towards scientific activities along with the inculcation of healthy habits for environmental protection. – The Authors

Textbook Features • Use of simple, age-appropriate language • Activity-based approach to learning • Use of infographics and pictures to explain concepts and terms • Focus on subject-related vocabulary building I Think I Will Learn About • Introduces the concept/ • Lists the key learning subtopic in a manner as to outcomes of the lesson arouse curiosity and interest among students ? In-text Questions Pin-Up-Note • Oral discussion questions to check for learning and to • H ighlights the key points or gauge the understanding definitions level of the child Connect the Dots A Be Amazed • F osters interdisciplinary • Fascinating facts and trivia thinking by connecting other related to the concept subjects to an aspect of the taught concept Inside the Lab A Note to Parent • H ands-on experience • Engaging activities to be done provided for creating, at home along with parents to designing or implementing reinforce the concept something innovative and/or useful based on the concept learnt

Contents 6 Plants and Plant Products ���������������������������������������������������������������������������..2 7 Forms of Matter ��������������������������������������������������������������������������������������������..8 8 Properties of Water ��������������������������������������������������������������������������������������14 Inside the Lab – B ������������������������������������������������������������������������������������������������20 Activity B1: How Plants Grow Activity B2: What is the Matter? 9 Water as a Resource �����������������������������������������������������������������������������������24 10 Sun as a Source of Energy �������������������������������������������������������������������������� 31 11 Healthy Surroundings, Healthy Body ��������������������������������������������������������� 37 Inside the Lab – C ������������������������������������������������������������������������������������������������.43 Activity C1: Clean Your Own Water Activity C2: The Sun is Powerful!

6Lesson Plants and Plant Products I Will Learn About • types of plants. • plant parts as food. • different plant products. • protecting the plants around us. I Think Rahil was walking in the school garden. He saw some very small plants and some very big plants. Have you seen any other types of plants? Types of plants We see different kinds of plants around us. Small plants Shrubs Hibiscus plant The plants which are very small and have weak, soft stems are called herbs. For example, mint, grass and Rose plant spinach. Herbs Plants that are taller than herbs and have woody stems are called shrubs. For example, rose and hibiscus. The stems of shrubs are Mint Spinach stronger than those of herbs. 2

Big plants Trees Some plants are big. They are called Mango tree Banyan tree trees. They have thick and broad, woody stems. They usually live for many years. For example, banyan tree and mango tree. Be Amaze A d Bamboos grow very fast. They can grow as tall as you within a week. Bamboos Plants that need support Climbers Creepers Pea plant Money plant Pumpkin Some plants cannot stand Watermelon straight without support. Such plants are called climbers. For example, money plant and pea plant. Some plants grow and spread along the ground. They are called creepers. For example, pumpkin and watermelon. ? Name some creepers. Plants are divided into following types: herbs, shrubs, trees, climbers and creepers. Plant parts as food You already know that plants have different parts, namely leaves, stems, flowers, fruits, seeds and roots. But do you know which parts of the plants we eat? Do we eat the whole plant or some parts of it? We may eat one or more parts of a plant as food. Plants and Plant Products 3

For example, leaves of spinach, roots of carrot, flowers We eat stems, of cauliflower, stems of sugar cane and so on. leaves, roots, fruits, flowers and seeds Let us see some more examples of plants and their of plants. parts that we eat. Stem as food Plant parts as food Flowers as food Potato Sugarcane Broccoli Cauliflower Fruits as food Seeds as food Tomato Mango Peas Peanuts Roots as food Leaves as food Carrot Beetroot Spinach Cabbage Different plant products We have studied how various parts of plants form the part of our food. Now, let us discuss the uses of plants in detail. 1) T he cooking oil we use is obtained from the seeds of plants such as sunflower, groundnut and so on. 2) W e add spices to make our food tasty. We get spices such as pepper, cardamom, clove and so on from plants. Clove Cardamom Pepper 4

3) We get tea from tea leaves and coffee from coffee beans. 4) W e get sugar from the juice of the sugarcane stem. 5) C ocoa beans are used to make delicious chocolates. 6) We get perfumes from flowers like jasmine and rose. We also use flowers to make beautiful garlands. 7) T he scented oils we get from some plants Flowers that are used to are used to make soaps, shampoos and make perfumes toothpaste. 8) Plants such as neem, amla, garlic, ginger and tulsi are used to make medicines. 9) T rees like teak, oak and mahogany give us wood. We use wood for making tables, chairs, spoons and so on. Wood from trees Chair Table 10) The pulp of bamboo is used to make paper. 11) W e get rubber from the juice of the rubber tree’s stem. Rubber is used to make tyres of vehicles, balloons, erasers and so on. 12) W e have learnt that we get cotton and jute fibres from plants. Leaves of some plants are also used to make brooms, doormats, roofs of huts and so on. 13) W e can make prints on clothes using Rubber juice from rubber tree plant colours. Colourful vegetables like carrot, beetroot and spinach can be used to make prints. Plants and Plant Products 5

Plants help us in many ways. But we still harm plants with our activities. We cut down trees for firewood, timber, medicines and so on. Due to the cutting of trees, many plants and animals have lost their homes and many more may disappear if we don’t protect them. Protecting the plants around us 1 2 We should We should not cut down grow more trees. plants. 3 4 We should put a We should not cage around baby pluck leaves plants to protect and flowers. them and should water them regularly. Connect the Dots English Fun Name the plants from the jumbled letters: 1) tmni : ______________________________ 2) ngrgie : ______________________________ 3) miupknp : ______________________________ 4) utsli : ______________________________ 6

Social Studies Fun Plants such as potato and chilli (or pepper) do not originally belong to India. They were brought to India from different countries of the world. A Note to Parent Let your child make a list of different plant products used at home. Help him/her find out the plants from which we get them. Plant products Plants from which we get them Plants and Plant Products 7

7Lesson Forms of Matter I Will Learn About • forms of matter: solids, liquids and gases. • properties of solids, liquids and gases. • uses of solids, liquids and gases in daily life. I Think Raman often wonders why things around us are different. Some of them have shapes, while some do not have. Some things can flow, while others cannot. Do you know why? We see many things around us. They are of different shapes, sizes, structures or forms. Have you ever wondered why the things around us are different from each other? Let us find out. Forms of matter: solids, liquids and gases Matter is everything that we can see, Everything around us is made up of matter. All matter touch/feel or smell. is made up of tiny particles. Matter takes up different forms based on how these tiny particles are arranged. Matter is made up of tiny particles. Matter in the solid form has a proper shape and size. For example, sugar, wood and paper. Matter in the liquid form takes the shape of the container it is kept in. For example, water, milk and so on. 8

Matter in the gaseous form has no shape. ? Name the three It moves around freely. For example, water different forms of vapour and air. matter. We know that water exists in three forms. Can you name the forms? These three forms are due to the arrangement of particles in the matter (water). Properties of solids, liquids and gases Let us now find out how particles are arranged in different states of matter. Try this! 1) Take your book, pen or pencil. Look at its shape. 2) Now, keep it in your bag. Does it change its shape? No. Thus, we can say that solids have a definite shape. The tiny particles in solids are tightly packed and cannot move. This arrangement gives them a definite shape. In liquids, the particles are not so tightly packed. They can Particle arrangement move. So, the liquids can flow from a higher level to a in solids lower level. They take the shape of the containers they are kept in. Liquids take the shape of their containers Loosely arranged particles in liquids In gases, the particles are far away from each other. Due to this, gases do not have a fixed shape. They can move easily in all directions. They take up the available space in any shape. You must have seen balloons of ? Which form of matter can move various shapes and sizes. How around freely in all directions? do we get such a variety of balloons? Forms of Matter 9

This is because the air in the balloons is in the gaseous form and can fill up space in any shape. Gases can spread in Gases can take up Very loosely arranged all directions the available space particles in gases Let us summarise the properties of different forms of matter. Solids Liquids Gases Arrangement of particles Shape Very close and Close but loosely Very loosely tightly packed packed arranged Have a definite Take the shape of Do not have a shape the container/vessel definite shape Ability to flow Can flow from higher Can flow in all Cannot flow levels to lower levels directions Uses of solids, liquids and gases in daily life We find matter in different forms in the air we breathe, the food we eat, the shelters we build, the clothes we wear and so on. • We use many solids in our day-to-day life. For example, classroom furniture, walls, books, pencils and so on. 10

• The food items we eat Food items in different forms of matter may be in all the three forms of matter. Most of the food items we eat are in solid or liquid form. However, soft drinks also contain gases in them. • Water, in the liquid form, is useful in many ways. It is used for drinking, bathing, watering plants and so on. Uses of water • T  he blood inside our body is in the liquid form. Its ability to flow helps it reach all our body parts. It carries nutrients and air. • We breathe in air. It is present everywhere. If air was in the solid or liquid form, we might not be able to breathe it. • Gases can give shape to objects. For example, the wheels of vehicles, balloons, air pillows and so on. • Air-filled objects float on water. They can help us swim. • Gases are also used to make soft drinks. Forms of Matter 11

dBe Amaze A Did you know that all the three states of matter are present inside our body? Our organs, bones and so on are in the solid form, our blood is in liquid form, and the air that we breathe in and out is in the form of gases. Our blood carries air with it. Connect the Dots Maths Fun Out of the 170 substances in a laboratory, 80 are in the solid form, 70 are in the liquid form, and the remaining are in the gaseous form. Find out the number of gaseous substances in the laboratory. H TO H TO 80 170 – + 70 English Fun Underline the nouns in the following sentences. a) Solids have a fixed shape. b) Liquids can flow. c) Gases can take up all the available space. 12

A Note to Parent Help your child to prepare a chart on the properties of forms of matter and the examples of different forms of matter that he/she encounters in day-to-day life. You may refer to the following samples. Forms of Matter 13

8Lesson Properties of Water I Will Learn About • water and its properties. • water soluble and insoluble substances. • conditions that affect the solubility of a substance in water. • making a simple solution. • objects that float or sink in water. I Think Rajat wanted to add some ice in his lime juice. He took out an ice tray from the freezer of his refrigerator and forgot to keep it back. What do you think happened after some time? Did the shape or size of the ice change? Water and its properties Water in nature exists in three different forms − solid (ice), liquid (water) and gas (steam or vapours). All forms of water show some common properties. Water in any form occupies space. Pure water in any form has no colour, smell or taste. 14

We can clearly see water and ice/snow. But it is difficult to see water vapour. We can see water changing into vapour when we boil it. There are some properties that are different for different forms of water. Differences between properties of ice, water and water vapour Ice Water Water vapour Shape Has a definite Takes the shape Does not have a shape of the vessel it is definite shape poured in Ability to flow Cannot flow Can flow in all Can flow from directions Ability to No higher levels to dissolve lower levels No substances Yes Water soluble and insoluble substances If we add some sugar to water and stir it for some time, the sugar disappears. What happens to the sugar? Where does it go? The sugar dissolves and the water looks the Sugar dissolves in water same as before. We can find out that the water has sugar in it only when we taste it. How to make a solution Solute Such liquids (and some solids and gases too) which can dissolve substances in them are called solvents. Water is the solvent in this example. The substances that get dissolved in a solvent are called solutes. Here, sugar is the solute. When a solute dissolves in a solvent, a solution is formed. Solvent Solution Properties of Water 15

Substances that can dissolve ? What do we call substances that in water are called soluble get dissolved in a solvent? substances. For example, salt, sugar and so on. Substances which do not dissolve in water are called insoluble substances. For example, wood, eraser, oil and so on. ? Name a substance that is soluble in water. Substances soluble in water may not be soluble in other liquids. Let us see an example. Like water, oil is also a liquid. Can we dissolve sugar in it? Try this! 1) Take a glass. Water can dissolve more substances 2) Add some cooking oil to it. than any other liquid. Hence, it is called the 3) N ow, add one spoon of sugar to it and stir. What universal solvent. do you observe? Sugar does not dissolve in oil. It remains at the bottom. Water, on the other hand, can dissolve a number of substances in it. So, it is called the universal solvent. Do substances insoluble in water dissolve in any other liquids? Yes. Let us see a few examples. 1) Some wall paints are insoluble in water. So, the painters use solvents like kerosene to wash away the paint from the brushes. 2) Oil is also insoluble in water. This is why we give oil or grease-stained clothes for dry cleaning. 3) Some other solvents like petrol are used for dry cleaning. The oil from the stains gets dissolved in it, and the clothes get clean. Oil paints are not water soluble 16

Be Amazed A Have you ever wondered why some soft drinks fizz when Fizzing soft drink can we open the lid? This is because they have carbon dioxide gas dissolved in water under pressure. So, when we open them, the carbon-dioxide gas present in the drink rushes out causing the fizzing. Conditions that affect the solubility of a substance in water Let us do some simple activities to see how we can dissolve sugar faster in water. Take a glass of water and a stop watch. Perform the below activities one by one. Tick the ones which are faster. (Note: You must take the help of your teacher while doing these activities.) S. No. Activity Observation 1 Add sugar to a glass of water and leave it. 2 Add sugar to a glass of water and stir it with a spoon. 3 Add powdered sugar to a glass of water. 4 Add sugar cubes to a glass of water. 5 Add sugar to cold water. 6 Add sugar to warm water. What did you observe? Stirring Powdered Sugar dissolves in water faster when: sugar 1) it is stirred, 2) the water is heated, 3) the size of the solute particles is small (powdered sugar). Heating Properties of Water 17

Making a simple solution You can prepare ORS using salt, sugar and water at home. Try this! You need: half teaspoon of salt, six Half 6 teaspoons teaspoons of sugar and teaspoon of sugar one litre of clean drinking or of salt boiled and cooled water. 1 litre of water - 5 You need to: cups full (each cup 1) Add the salt and sugar is about 200 to 1 litre water. ml) 2) Stir the mixture till the salt and sugar dissolve in water. We drink this solution (ORS) when we fall sick and feel weak. Objects that float or sink in water Do all the things we add to water get dissolved in it? We know that some substances are insoluble in water. Let us see what happens when we add such substances to water. Try this! 1) Take a small piece of wood or a rubber ball. Put it in water. What happens? It remains near the surface. 2) Stir the water. Does anything happen? No. It remains as it is. Wood and rubber do not dissolve in water. They float on the surface. 3) Now, put some sand in the water and stir. What do you notice? Does the sand dissolve in water? No. It just goes down and settles at the bottom. Sand neither floats nor dissolves in water. It sinks to the bottom. Let us find out about some more objects that sink or float in water. Try this! 1) Take a small piece of paper. Put it in water. What happens? It remains on the surface. 18

2) Stir the water. Does anything happen? No. It remains the same. Paper does not dissolve in water. It floats on the surface when it is dry. This is the reason why a paper boat also floats. What happens if the paper gets wet? It sinks in the water. Try this! Now, put a piece of chalk in a glass of water. What do Chalk sinks in water you see? Does it disappear in water? Does it float on the surface of water? No. It goes down and settles at the bottom of the glass. The chalk piece neither floats nor dissolves in water. It sinks in water. Connect the Dots Social Studies Fun A man floating on the Dead Sea The water of a sea, called The Dead Sea has very high level of salts dissolved in it. So, most of the water plants and animals cannot live in it. This is why it got the name ‘Dead Sea’. Anyone can easily float on the Dead Sea due to the high amount of salt in it. English Fun Fill in the blanks using the correct prepositions. 1) Sugar dissolves ____________________________________ water. 2) A leaf floats ____________________________________ the surface of water. 3) Stone sinks ____________________________________ water. A Note to Parent Discuss with your child the uses of water as a solvent in day-to-day life. For example, the drinks and food items you prepare using water. Properties of Water 19

B Inside the Lab Make sure you do these activities only with the help of a teacher or an adult. Activity B1: How Plants Grow We have learnt that seeds need moisture, air and the right amount of warmth to germinate and grow. Let us do a seed germination activity to find out whether the seeds need all these to germinate or not. You will need: bean seeds(15–20 per bowl), 5 clean and empty bowls(one for each condition), paper towels, water to wet the towels and the, masking tape to label the bowls. You need to: 1) Keep the seeds in the following conditions. Bowl 1 How Where Bowl 2 Place the seeds on a wet paper towel. In air and sunlight Bowl 3 Place dry seeds. In air and sunlight Bowl 4 Pour water in the bowl. Put the seeds in water. In air and sunlight Bowl 5 Place the seeds on a wet paper towel. In a dark place Place the seeds on a wet paper towel. In the refrigerator Bowl 1 Bowl 2 Bowl 3 Bowl 4 Bowl 5 In air and sunlight Dark place Refrigerator 20

2) M ake predictions about what will happen. Note them down in your observation sheet. 3) T ake a look at the bowls 7 to 10 days later. Note down your results in the observation table given below. 4) W hat do you notice? The seeds kept in which bowl/bowls germinate? Which do not? Note: • The seeds under water will need to have their water changed regularly, so that mould growth does not take over. • Check once a day to ensure that the paper towel is wet. Observation table: Experiment Conditions Prediction Actual Result Actual Result number after ____ days after ____ days 1) 2) 3) 4) 5) Inside the Lab – B 21

Activity B2: What is the Matter? You know the various states of matter and some of their properties. Now, let us learn to identify the states of matter around us. You will need: cooking oil, sugar cubes, milk, cold water, hot water, inflated balloon, lighted incense stick (agarbatti), sand, glass tumbler, empty bottle and so on. You need to: 1) Take the samples one by one and observe them carefully. 22

2) T ry to identify which state of matter they belong to by answering a series of questions. Example: • Take one sugar cube. Does it have a fixed shape? Yes! • N ow, put it in a tumbler. Does it change its shape depending on the shape of the tumbler? No! • Now put it on the ground; does it flow? No! • Which type of matter shows such properties? Solid. Thus, it means sugar cube is a solid. 3) R epeat the activity for each of the given samples and answer the same set of questions for each item. Classify the items as solids, liquids and gases and write in the following table. You can try this with many more samples to identify their state as matter. Solid Liquid Gas Inside the Lab – B 23

9Lesson Water as a Resource I Will Learn About • forms of water. • the water cycle. • impurities in water. • reasons for impurities. • ways to purify water. • ways to save water. • rainwater harvesting. I Think While going to school, Aslam saw a puddle. But while coming back from school, he found that it had dried up. Where did the water go? Puddle Forms of water We already know that water exists in three forms – ice (solid), water (liquid) and water vapour (gas). To change water from one form to another, we need heat. Let us learn this with the help of some activities. Try this! Ice cubes melt to form water 1) T ake some ice cubes in a container. Keep them for some time. What do you see? The ice melts to form water. 24

2) N  ow, add some water to Water changes to water Water vapour is cooled a container and boil it on a stove. What happens? vapour on boiling down to change to Water starts changing into water vapour. water again 3) T  hen, hold a steel plate or lid over the container with boiling water. What do you see? Tiny drops of water are collected on the plate. From these activities, we know that when ice is kept outside the freezer, it changes to water after some time. It takes heat from the surroundings. When we boil water, it changes to water vapour. If this water vapour is cooled, then it changes to water again. If we pour this water into an ice tray and keep it in the freezer of a refrigerator, the water changes back to ice. The water cycle During daytime, heat from the Sun changes the water in water bodies into water vapour. The water vapour tends to go upwards, where it cools down. It forms small water droplets on cooling. These water droplets form clouds in the sky along with dust. Inside the clouds, the water droplets Water cycle combine to form big drops. When these big drops become too heavy, they fall as rain. Some of this rainwater gets collected in water bodies like rivers, ponds, lakes and oceans. Water as a Resource 25

Some water goes down the soil and is stored Water moves from the land underground. to the air, and back to the During winter, in very cold places, water water bodies, changing changes to ice and snow. between the solid (ice, snow), liquid (rain, water) This process where water changes its form and and gas forms(water moves from water bodies to clouds and from vapour) in a process called clouds to water bodies again is called water water cycle. cycle. Impurities in water Most of our Earth is covered with water. But we cannot use all the water for drinking. Seawater has dissolved salts and is unfit for drinking. We get drinking water from rivers, wells, lakes and so Impurities in water on. It may contain substances like mud, dirt, sand and make the water unfit germs. This water is unfit for drinking too. It contains for drinking. These impurities. impurities are of two types – soluble and Some impurities like salt and chemicals from factories insoluble. mix with water. They are soluble impurities. Some impurities like mud, plastic and sand ? Name any insoluble do not mix with water. They are insoluble impurity. impurities. Reasons for impurities 1) W aste and chemicals from factories are let out in nearby rivers, ponds and lakes. 2) Many chemicals are used to grow plants on farms. These chemicals get mixed with the soil and then get into the underground water. 3) In villages and small towns, the practices of washing clothes and utensils and bathing animals in rivers and lakes add soap, dirt and waste to the water body. 4) Some people do not have the toilet facility at home. So, they defecate and urinate on the banks of rivers and lakes. Ways to purify water 1) When we leave muddy water to stand still for some time, the mud and sand settles at the bottom. The clear water on the top can then be poured into another vessel and used. 26

Water Sand and mud Sand and mud Clear water Separating clean water from sand and mud 2) We can pass water slowly through a sieve or mesh called a filter to separate the clean water from insoluble impurities. Different types of filters include thin cloth, clay, layers of sand, gravel and charcoal. Some types of filters This filtered water may not be fit for drinking. It may look clean to our eyes, but it may have germs in it. The process of Some methods to remove the germs from water are: removing all unwanted • Boiling the water for 10-15 minutes and unhealthy substances from water • Adding chemicals like chlorine (This method is to make it clean and used to purify large amounts of water.) safe for use is called • Using water purifiers water purification. ? Which chemical is added to water to kill germs? Water as a Resource 27

Ways to save water We use water for various purposes. But limited fresh water is available. So, we need to save it. Making small changes in our daily life can help us save a lot of water. Some of these changes are: Avoid flushing the Take showers for less toilet unnecessarily. time or use a bucket to Use half-flush instead. bathe. Use a watering can instead of a hose. Check your Turn off the tap while toilets and brushing your teeth, taps for scrubbing your hands and leaks. shampooing your hair. dBe Amaze A If we reduce our shower timing to 4 minutes, we can save about 60 litres of water every day. 28

Rainwater harvesting In this method, the rainwater is collected in tanks or allowed to go underground. The collected water can be used for cleaning purposes, washing laundry and watering plants. When purified, rainwater can also be used for drinking. Rainwater harvesting Water is a precious resource. We are facing a shortage of water nowadays. We need to conserve water. Hence, rainwater harvesting is necessary. We can use this water later during the dry seasons for various purposes. ? State any one purpose for which we can use the stored rainwater. Water as a Resource 29

Connect the Dots English Fun Anu is a drop of water. She lives in a pond. Anu was feeling very hot on a hot summer afternoon. She decided to travel. Can you tell where Anu will go from the pond, on a bright, sunny afternoon? (Hint: Anu is a water droplet. What happens to a water droplet when it is hot? It follows the water cycle. Now, complete the story of Anu’s journey!) __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ Social Studies Fun Many people do not have access to clean drinking water. There are organisations that are helping to provide clean water to people around the world. Some of them are: TAP PROJECT, water.org and Charity: Water. A Note to Parent Discuss with your child the importance of water purification. Help him/her make a simple water filter at home using sand, gravel and a thin cloth. 30

Sun as a Source 10Lesson of Energy I Will Learn About • energy and its sources. • the importance of solar energy for all living things. • the need of solar energy for food production in plants. • the use of solar energy in daily activities during different seasons. • ways to capture solar energy for daily use. • renewable and non-renewable sources of energy. I Think Nina’s parents always tell her to drink milk and eat vegetables. They say it will help her get energy. Do you know what energy is? Energy and its sources Energy is the ability to do work. We need energy to get out of bed in the morning. We need energy to run, jump and play. Cars need energy to move. The computer needs energy to work. We get energy from food. Cars get energy from fuels. The computer gets energy from electricity. Energy is the ability to do work. The Sun The Sun is the main source of energy available to all is the main source of living things on Earth. The energy that we get from energy on Earth. the Sun is called solar energy. 31

The importance of solar energy for all living things We get solar energy in the Without the Sun, life is not possible on the Earth. It provides form of heat heat and light that are necessary for the growth of plants and light. and animals. ? In what form, do we get solar energy? The need of solar energy for food production in plants Air Plants cannot make their food without sunlight. Leaves of Sunlight green plants use sunlight along with water and air to make their food. This process is called photosynthesis. This food is Water stored in different plant parts. Some energy is used for the Photosynthesis growth of the plant. Be Amaze A d Sunlight takes around 8 minutes to travel from the Sun to reach the Earth. The uses of solar energy in daily activities during different seasons The availability of sunlight varies during different seasons of the year. We plan some of our day-to-day tasks according to the availability of sunlight. Let us see what we do during different seasons. Summer season: We dry clothes under the Sun. We make pickles and sun-dry them. We can sun-dry and preserve other food items, too. Winter season: The Sun keeps us warm during winters. We can sit and enjoy under the Sun. Rainy season: The presence of the Activities in spring Sun during the rainy season helps us to dry our clothes quickly. We can also spot rainbows sometimes when the Sun shines during rains. 32

Autumn season: The Sun keeps us warm during this season when the heat starts to decrease. Autumn is an ideal time to plan for picnics as the weather is pleasant during the autumn season. Spring season: The Sun keeps the weather warm, trees begin to grow their leaves, and plants start to flower in the spring season. It provides good weather for outdoor activities. Ways to capture solar energy for daily use We can use solar panels to capture sunlight and convert it to electricity. Solar panels consist of many solar cells. They convert solar energy to electricity. This electricity can be used to light our homes, street lights, offices, public places and so on at night. S olar cookers use the rays of the Sun and concentrate them in a small area. This increases the heat inside a solar cooker, and the food gets cooked. They are very cheap and environment-friendly. Also, they help us save cooking gas. Similarly, solar heaters are a good alternative to electricity or gas for heating water. Solar panels Solar cooker Solar heaters on the roof of a house ? State two uses of solar energy. Renewable and non-renewable sources of energy The Sun is burning continuously to provide energy. The Sun, wind and water This is the source of energy that will last for a long are renewable energy period of time. Like the Sun, there are some other sources. Coal, petrol, sources of energy such as the wind and water that diesel and cooking will last for a long time. Such energy sources are gas are non-renewable called renewable energy sources. energy sources. Sun as a Source of Energy 33

There are other energy sources that will not last for a long time. These are called non-renewable energy sources, for example, coal, petrol, diesel and cooking gas. These resources can easily be used up. So, we should use them carefully and not waste them. Ways to save energy: We can save energy at home or school in the following ways. 1) We should switch off fans and lights in our classroom or at home before leaving. This saves electricity. 2) We should not keep the refrigerator door open. 3) We should turn off our televisions and computers when not in use. 4) We should choose to walk or use a bicycle to go to nearby places. This will help to save fuel. 5) We should use CFL and LED lamps instead of ordinary bulbs and tube lights at home. This will save energy. 6) We should turn off water geysers when not in use. Some ways to save energy ? Name a type of lamp that can be used to save energy. 34

Connect the Dots English Fun Adjectives are describing words. For example, a beautiful flower; here, ‘beautiful’ is describing a flower. 1) Identify and underline the adjectives in the following terms. a) solar energy b) dry clothes c) warm weather d) renewable energy 2) Give the opposites for the following words. a) hot: ____________________________________________________________ b) light: _____________________________________________________________ Social Studies Fun Heat rays used by Archimedes In ancient times, in a country named Greece, Archimedes, a Greek mathematician, used solar energy to defeat his enemies. He used ‘heat rays’ to burn the ships. Find out how. (Hint: using a mirror to focus the Sun’s rays on the ships) Sun as a Source of Energy 35

A Note to Parent Help your child to identify and list different renewable and non-renewable sources of energy used at home. For example, solar energy used to dry our clothes is a renewable source, while petrol used in vehicles is a non-renewable source of energy and so on. Renewable sources Non-renewable sources 36

Healthy 11Lesson Surroundings, Healthy Body I Will Learn About • the need for healthy living. • ways to live a healthy life. • the need for healthy surroundings. • causes of unhealthy surroundings. • ways to improve our surroundings. • Swachh Bharat Abhiyan. I Think Every morning, Sandhya does yoga for 30 minutes. On the other hand, her friend Rama wakes up late and does not exercise at all. Who do you think will be healthier of the two? Yoga The need for healthy living We already know that personal cleanliness is very important for a healthy body. If we do not take care of our body properly, we fall sick. When we are sick, we cannot do our everyday work normally. Let us find out how we can lead a healthy life. 37

Ways to live a healthy life Personal cleanliness, eating healthy food, taking proper rest and doing exercise are the keys to a healthy life. Can you recall what are the healthy habits that we need to follow? Handwashing: • W e need to wash our hands properly before and after meals. • W e should also wash our hands with soap after using the toilet. • After playing, we must wash our hands to Washing hands with soap remove dirt and mud. Oral hygiene: • We should brush our teeth twice daily – once in the morning and again before going to bed. • After every meal, we should rinse our mouths Rinsing mouth with water with water. It will remove the food particles inside the mouths and between our teeth. Bathing: • We should bathe daily using a soap. • We should not avoid taking a bath. • We should take a warm bath in winters. Hair care: • We should comb our hair regularly. A child having a bath • When we travel or play outdoors, our hair become dirty. Dandruff and sweat may also make our hair dirty. So, we should wash our hair properly while bathing. • We should use a good hair oil and shampoo to keep our hair clean. A girl combing her hair 38

Food: Our food should include: • energy-giving food items like oil, sugar, potato, rice and so on. • body-building food items like milk, eggs, meat, fish and pulses. • fruits and vegetables to protect us from illnesses. Moreover, we should avoid eating junk food. Water: Drinking at least 6-8 glasses of water daily is important for good health. Rest: To take care of our body, it is important to take proper rest. We should sleep for at least 7-8 hours daily. Going early to bed and waking up early are important for a healthy body. Exercise, yoga and recreational activities: ? How many hours of Exercise, outdoor games and other activities sleep do we need like dancing, swimming and so on make our daily to be healthy? body strong and keep us happy. Yoga and meditation help our body relax. Being worried or angry about anything makes our body weak. This can also make us fall sick easily. The need for healthy surroundings Clean surroundings are important for healthy living. Unhealthy air, water and soil cause many problems and diseases in animals and human beings. So we must keep our surroundings clean. But how do our surroundings become unhealthy? Causes of unhealthy surroundings Many of our activities make our surroundings dirty and unhealthy. Throwing garbage: Many people throw away waste in open fields. Some of it decays and stinks. Also, flies and worms sit on it and spread germs. This may lead to diseases. Some bury plastic and other harmful waste in the soil. Dry waste like broken pieces of glasses or nails can also harm us. Healthy Surroundings, Healthy Body 39

Polythene: It is widely used for packaging, as shopping bags and so on. When not disposed of properly, it may also lead to the death of animals like cows and goats by choking. If buried in the soil, polythene makes the soil unfit for living things. Spitting, urinating and defecating in the open: Some Throwing garbage people have the habit of spitting on the roads. Some and polythene, people chew tobacco and spit here and there spitting in public making the surroundings dirty. places and urinating and defecating Urinating in public places makes the surroundings in the open make dirty and smelly. Some people defecate in the open. the surroundings It pollutes the nearby water sources and causes unhealthy. diseases, such as typhoid and cholera. Ways to improve our surroundings Let us look at some ways to keep our surroundings clean and healthy. 1) W e must throw waste in dustbins only. We should sort them before disposal. Sorted waste materials can be disposed of in separate bins. Bins of different colours and labels make it easy to dispose of the sorted waste. 2) We should not burn or bury polythene in the soil. 3) W e should not spit on roads or public places. We should only use toilets for urination or defecation. 4) We can reduce the problems caused due to Bins for waste disposal waste through reduce, reuse, recycle method (3R Method). • Reduce: Use of certain harmful things can be reduced, for example, plastic bags. We can use paper or jute bags in place of polythene. • Reuse: We should reuse things to the maximum. For example, we can donate some old clothes, toys, or other things, which are in a good condition. They can be reused by needy people. • Recycle: Have you seen a person who collects old newspapers, bottles and boxes? New, useful things can be made ? What is recycling? from such waste. This is called recycling. For example, old newspapers collected from houses are changed into paper pulp. 40

dThings like paper cups and dishes are made from the pulp. Recycling Have you seen this sign anywhere? It is used to show materials which can be recycled. Be Amaze A Paper is made from the wood of trees. If we recycle 1000 kg of paper, we can save around 17 trees from getting cut. Swachh Bharat Abhiyan To make India a clean country, the Government of India had started the Swachh Bharat Abhiyan in the year 2014. The aim of this cleanliness drive is to completely end open defecation in our country. Connect the Dots English Fun Write any four adjectives which describe garbage. For example, dirty. 1) ___________________________________________ 2) ___________________________________________ 3) ___________________________________________ 4) ___________________________________________ Healthy Surroundings, Healthy Body 41

Social Studies Fun In India, the government conducts surveys to check the cleanliness of Indian cities. Based on the surveys, the cities are ranked. In 2016, the three cities which topped the ranking were Mysore, Chandigarh and Tiruchirapalli. A Note to Parent Encourage your child to play his/her favourite outdoor games daily. Discuss with your child the benefits of activities like cycling, swimming, dancing, gardening and so on. Make a weekly activity chart for your child in the space given below. Day of the week Activity Sunday Monday Tuesday Wednesday Thursday Friday Saturday 42

C Inside the Lab Make sure you do these activities only with the help of a teacher or an adult. Activity C1: Clean Your Own Water Let us now make a simple water filter. You will need: a large plastic bottle, a container, a piece of cotton cloth, gravel, sand and muddy water. You need to: 1) M  ake 10 holes in the bottom of the large, empty plastic bottle. 2) Cut off the top of the bottle evenly. (The teacher should help the learners while cutting.) 3) S  pread the cotton cloth at the bottom covering all the holes. 4) Add a layer of gravel. 5) Then, fill the bottle with sand. Muddy water Water bottle 6) N  ow, pour the muddy water through the homemade filter. Sand Gravel 7) R  etrieve it in another container from the Cotton cloth bottom. Clean water 8) L  ook at the water that comes out of the Container filter. It should be clear. If not, you may have to pass the water through the filter Simple water filter more than once. Note: Now you have made a water filter, but the water you get may not be safe to drink. The water may still contain harmful bacteria that your filter did not remove. To get water safe enough to drink, you also need to purify it. 43

Activity C2: The Sun is Powerful! Let us use sunlight and a magnifying glass to make fire. You will need: a piece of paper, small pieces of dry wood, a magnifying glass and a bucket of water to put out the fire You need to: 1) T  ake a piece of paper to an open ground, where you get bright sunlight. (Carefully select a place where the fire cannot spread and burn anything else.) 2) T  ake a small piece of dry wood, and place the paper over it. 3) H  old the magnifying glass in such a way that the sunlight falls on it, and all the light is focused on the paper. A small, bright dot will appear on the paper. 4) H  ave patience, and wait for some time. After a while, you can see that the paper catches fire. 5) P  ut out the fire as soon as it ignites by pouring water. (Take help from your teacher.) 44


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