242510237-HAZELWOOD-STUDENT-TEXTBOOK-EVS_I(SCIENCE)-G03-PART1

Hazelwood G3 EVS-I TB P1_Nameslip 1.pdf 1 8/7/2023 12:25:09 PM Name: _________________________________________ Section: ________________ Roll No.: ______________ School: ________________________________________ EVS - I (SCIENCE) TEXTBOOK Part - 1

PREFACE The latest National Curriculum Framework (NCF), furthering 1 the vision of the National Education Policy (NEP) 2020, provides a comprehensive framework for the holistic 5 2 development of students. It places a strong emphasis on 4 foundational literacy and numeracy and a competency-based and learner-centred approach to ensure a well-rounded education that prepares students for the challenges of the 21st century. ClassKlap by Eupheus partners with schools and supports them through the steps of planning, teaching, learning, 3 personal revision and assessment to equip students with the desired knowledge and skills relevant to the 21st century. The present series has been carefully crafted to provide a solid foundation for students keeping in mind the principles outlined in the NCF. The books promote active learning and skill development. They strive to ensure inclusiveness in terms of gender and diversity in representation, catering to the heterogeneous Indian classroom. The books have been split into two parts for lighter bag weight. To facilitate comprehensive coverage, improved understanding of diverse themes and ease of implementation, the EVS curriculum has been split into EVS–I (Science) and EVS–II (Social Studies). The salient features of the EVS–I (Science) textbooks and workbooks are as follows: Skill-based lessons are structured as per Bloom’s Revised Taxonomy (Remember-Understand-Apply-Analyse-Evaluate-Create) Inquiry-based lessons are structured based on a Socratic approach using a question-answer format, aiming at discovery-based learning as per NCF guidelines Interactive content that engages students through a range of open-ended questions that build curiosity and instil a passion for scientific exploration A structured and coherent progression of concepts to build a foundation of scientific knowledge and skills Opportunities for experimentation, analysis and synthesis of ideas and concepts and encouragement of evidence-based thinking Effective use of visual elements to enable learning of structures, processes and phenomena A focus on subject-specific vocabulary building Integrated learning of values and life skills through the content and activities Fostering interdisciplinary learning by connecting themes and concepts across subjects The EVS–I (Science) textbooks, workbooks and teacher companion books aim to inculcate healthy habits, skills and values that promote environmentally sensitive and culturally responsive democratic citizenship among students. 20-21_Science_G3_TB_CE_Part1.indd 2 7/31/2023 12:21:08 PM

ENTGELXITSBHOOCKOFUERATSUERBEOSOK FEATURES Art-Integrated Learning Let Us Learn About Lesson plans provided for Indicates the learning outcomes to be covered in the lesson art-integrated learning Remembering SKILL-BASED LESSONS Introduces new concepts by building on the prerequisite knowledge or skills Think Understanding Introduces the concept and arouses curiosity about it among students Explains the sub-concepts that form the basis of the concept in detail Application Amazing Facts Focuses on the application of the concepts and connects them to real-life scenarios Fascinating facts and trivia related to the concept Higher Order Thinking Skills (H.O.T.S.) Connect the Dots Encourages students to extend the concept A multidisciplinary section to connect learnt to advanced application scenarios the lesson theme with other subjects Inside the Lab Reflection Time! Thought-provoking questions to Hands-on activities that involve creating, encourage reflection on the concept and designing and implementing something on how it is related to the student's life, innovative and useful related to the concepts experiences and the world around INQUIRY-BASED LESSONS Concepts organised using a question-answer approach to foster a mindset of inquiry and reasoning Science_G3_TB_Part1.indb 3 7/28/2023 3:42:24 PM

Contents Class 3 1 My Hobbies Art-Integrated Learning    Skill-Based ������������������������������������������������������� 1 2 Family as First School Art-Integrated Learning    Inquiry-Based ������������������������������������������������� 5 3 Organ Systems Skill-Based ���������������������������������������������������������������������������������� 8 4 Skeletal System Skill-Based ������������������������������������������������������������������������������� 12 5 Way around Our Neighbourhood Art-Integrated Learning    Skill-Based ����������������������������������������������������� 16 6 Forms of Water Art-Integrated Learning    Skill-Based ����������������������������������������������������� 20 Inside the Lab – A������������������������������������������������������������������������������������������������������������� 24 Activity A1: Salt from Seawater Activity A2: Create Your Compass 7 S ources of Light Inquiry-Based �������������������������������������������������������������������������� 26 Science_G3_TB_Part1.indb 4 7/28/2023 3:42:26 PM

Lesson My Hobbies 1 Let Us Learn About R hobbies and their types. U how hobbies are useful to us. A choosing a hobby as a job. H my parents’ hobbies. Think Sam likes to watch movies in his free time. His sister likes photography. They enjoy doing these activities. What are such activities, that you enjoy doing, called? Remembering You go to school every day to learn new things. You play with your friends at school. What do you do after school? At home, you do homework, watch TV, play and help your parents. How do you spend your free time on Sundays and holidays? Science_G3_TB_Part1.indb 1 different types of activities 1 7/28/2023 3:42:28 PM

Some of the activities that you may enjoy doing are shown below. Guess what they are. They are called hobbies. Hobbies are the activities that we do for relaxation when we have free time. There are different types of hobbies. They are shown in the chart given below: Types of hobbies sports outdoor arts collection making and coins games recreation painting stamps scrapbook leaves making football birdwatching singing feathers knitting stargazing reading and pottery badminton cooking writing cricket gardening dancing video games travelling photography yoga trekking running mountaineering swimming adventure sports 2 7/28/2023 3:42:32 PM Science_G3_TB_Part1.indb 2

Understanding HOW ARE HOBBIES HELPFUL TO US? People take up hobbies to be happy. But there are other benefits of hobbies too. Some of the benefits are as follows: 1) They keep us healthy: Hobbies like exercising, sports and games keep us healthy. 2) They help us to be creative: Hobbies like painting, writing and cooking help us to create something new. 3) They help us to make useful things: Hobbies like knitting and pottery help us to make useful things. 4) They help us to learn new things: Hobbies like reading books help us to learn new things. A collection of stamps and coins helps us learn about different countries. 5) They teach us to work in groups: All hobbies which involve group activities teach us to work in groups. For example, games like football, hockey and so on. Group dancing also helps us learn to work in groups. Application You have learnt about the benefits of hobbies. Do all your friends have the same hobbies? One of your friends may like to play video games. Another friend may like to play badminton. Do you and your siblings like the same games or activities? Some of your choices may be the same and some may be different. What could be the reason? People choose a hobby that they playing video game playing badminton find interesting. Different people have different likes and dislikes. Therefore, different people have different hobbies. If we practise a hobby for a long time, we become good at it. Then, we can carry forward that hobby as a job. My Hobbies 3 Science_G3_TB_Part1.indb 3 7/28/2023 3:42:34 PM

For many people, their hobbies become V. V. S. Laxman J. K. Rowling their jobs when they grow up. For example, V. V. S. Laxman, the Indian cricketer, was good at studies. However, he became a great batsman as playing cricket was his hobby. The famous author of the Harry Potter series—J. K. Rowling—wrote stories as a hobby. Her hobby has become her job. Discuss your hobbies with your friends. Make a list of one another’s hobbies. Write what your friends want to become when they grow up. Your friends’ hobbies What your friends want to become Amazing Facts Philately is the hobby of collecting stamps. It is called the king of all hobbies as it is one of the most popular hobbies in the world! a collection of stamps Higher Order Thinking Skills (H.O.T.S.) Everyone has hobbies. What hobbies do your parents have? Did they have hobbies similar to yours when they were of your age? What could be the reason behind this? Find out. Connect the Dots English Fun Find the names of hobbies hidden in these jumbled letters. 1) rwadngi 2) sngigni 3) ottpery 4) goya 4 7/28/2023 3:42:35 PM Science_G3_TB_Part1.indb 4

Lesson 2 Family as First School We all live with our families. They are the ones we spend the most time with. Each family is different but we all learn many things from our families. What do we learn from our families? We learn all kinds of things from our families. But mainly, we learn habits and values from our families. That is why we can call our families our first school! What are habits and values? Habits are activities we do daily. For example, waking waking up brushing exercising up early, brushing twice a day, exercising, etc. What are some of the habits we learn from our family? • the type of food we eat • the way we eat • our table manners • at what time we go to bed and wake up learning table manners • how loudly or softly we laugh or talk from parents Science_G3_TB_Part1.indb 5 5 7/28/2023 3:42:47 PM

respecting Values are good thoughts and actions. They help us taking care of elders decide what is right or wrong. For example, respecting younger ones elders, looking after those who are younger, being polite, and so on. What values do we learn from our families? We learn all kinds of values from our families. Here are some examples. Being kind and helpful: What happens when you are sick? Your family takes care of you and helps you get better. Family teaches you to help and take care of others. Respecting others: Your parents talk to their elders with respect. They listen to what the elders have to say. You learn to be respectful to your elders. Being disciplined: Your parents get up on time and do the household chores. They help you get ready for school. Then, they go to work. They have taught you to wake up early and not be late for school. Do all families have the same habits and values? No, habits and values within each family are different. In some families, the family members: • touch the feet of elders praying before • keep their footwear outside the house a meal • eat meals and celebrate festivals together • pray before meals, and so on Do your family members follow any of these practices? Tick the ones that they do. Have you ever thought about what you have learnt from your family? Think of any three habits or values and share with your partner. 6 7/28/2023 3:42:49 PM Science_G3_TB_Part1.indb 6

Reflection Time! 1) Do you think that all the things we learn from others can be good for us? 2) Do your parents or teachers say that you have learnt some bad habits? How can we make sure that we learn only good things from others? 3) What is the best habit that you have learnt from your family? Family as First School 7 Science_G3_TB_Part1.indb 7 7/28/2023 3:42:50 PM

Lesson Organ Systems 3 Let Us Learn About R organs inside the body. U different organ systems and their parts. A the effect of daily activities on organ systems. H the position of different organs inside the body. Think When we breathe in, we take in air. Where does this air go? It goes inside our body. Let us find out what is inside our body. Remembering We have many special body parts. The parts of the body that help us to do special and important work are called organs. We can see some organs from outside the body. However, there are some organs that are inside the body. We cannot see them. ORGANS INSIDE OUR BODY Food pipe: It is a tube which goes from the mouth through the throat to the stomach. 8 7/28/2023 3:42:55 PM Science_G3_TB_Part1.indb 8

Stomach: It is a sack-like organ. When we eat food pipe food, it goes into the stomach through the food pipe. stomach food pipe and stomach Windpipe: It is a tube that connects the throat to the lungs. It is also called the trachea. windpipe Lungs: There is a pair of lungs in the chest. lung H eart: It is located a little to the left of the lungs heart middle of our chest. It is about the size of our fist. kidneys brain Kidneys: We have a pair of kidneys. They are bean-shaped. Brain: It is present inside the head. Some organs inside our body form a group to do specific tasks. Such a group of organs is called an organ system. There are many such organ systems. Examples of some organ systems are the digestive system, circulatory system, skeletal system, muscular system and so on. Understanding SOME IMPORTANT ORGAN SYSTEMS mouth food pipe Our body has many organs and organ systems. They work together to carry out different tasks. stomach intestines The digestive system helps to take in food through our mouth and food pipe. In our stomach, the food is broken down to make it easy to digest (just like a mixer-grinder). The digestive system consists of the mouth, food pipe, stomach and intestines. digestive system Organ Systems 9 Science_G3_TB_Part1.indb 9 7/28/2023 3:42:55 PM

The respiratory system helps in breathing. The organs of this system are the nose, windpipe and lungs. The circulatory system sends blood to all parts of heart the body. The heart is the most important organ in this system. It pumps blood to all the parts of blood the body just like a water pump. Blood flows in vessels our body through blood vessels (thin tubes like water pipes). Our brain, nerves and spinal cord together make our nervous system. It is the control center for our entire body. Our brain uses the information it receives from our nerves to control all activities of our body. It helps us to think and learn. circulatory system Application Now, you know about the different organ systems and how they work. Can we control all these organs? We cannot directly control the organs inside our body. The brain works even when you are sleeping. You breathe continuously when you are running, eating or sleeping. Is the breathing faster or slower when you are doing these activities? The heart beats continuously. Does the heart rate always remain the same or does it change? Amazing Facts A child’s heart beats faster than an adult’s. Your heartbeat changes depending on the type of music you are listening to. 10 7/28/2023 3:42:56 PM Science_G3_TB_Part1.indb 10

Higher Order Thinking Skills (H.O.T.S.) Draw an outline of the human body on a cardboard and cut it out. Then, draw the different organs present inside our body on a piece of paper. Colour them. Cut out the organ shapes. Can you place these organ shapes correctly on the cutout of the body? To do this activity, you will need: a piece of cardboard, a piece of paper, pencil, crayons, scissors, gum cutout of the body and organs Connect the Dots Maths Fun Suppose your heart beats 90 times a minute. How many times will it beat in 10 minutes? Organ Systems 11 Science_G3_TB_Part1.indb 11 7/28/2023 3:42:57 PM

Lesson Skeletal System 4 Let Us Learn About R the skeletal system. U the functions of the skeletal system. A keeping our bones healthy. H the skeletal system in animals. Think Asif fell while cycling. He hurt his leg. His mother took him to the doctor. The doctor asked them to get an x-ray picture of the leg. Do you know what an x-ray picture tells us? an x-ray picture of the leg Remembering Hold your wrist tightly. Do you feel something hard inside it? It is a bone. Our body has many bones. At birth, we have around 300 bones. As we grow, some bones fuse and join. Adults have 206 bones. Joints are places where two bones meet. Example: knee, elbow All the bones in our body together form the skeletal system. 12 7/28/2023 3:42:59 PM Science_G3_TB_Part1.indb 12

IMPORTANT PARTS OF THE SKELETAL SYSTEM skull Skull: Bones in the head form the skull. rib cage backbone Ribs: Bones around the chest form the ribs. The ribs join in the front and back to form the rib cage. Backbone: Many small bones (vertebrae) join to form a rod-like structure called the backbone. It connects the neck to the lower back of our body. It is also called the vertebral column. human skeletal system Understanding FUNCTIONS OF THE SKELETAL SYSTEM 1) The skeletal system gives shape and support to our body. For example, bones in the skull give shape to our head and face while the backbone helps us to stay erect. Imagine how your body will be without a backbone! Bones store minerals inside them. These minerals make them strong enough to support our body. 2) The skeletal system protects the organs inside our body. For example, the rib cage protects the lungs and the heart while the skull protects the brain. skull rib cage brain lung heart skull rib cage Science_G3_TB_Part1.indb 13 Skeletal System 13 7/28/2023 3:43:01 PM

3) The skeletal system helps us to move. Joints help our body to twist and turn. For example, leg joints help us to walk and run. Application HOW CAN WE KEEP OUR BONES STRONG AND HEALTHY? Healthy food: Vitamins and minerals like calcium make our bones strong. So, we must eat food items which contain these nutrients. Leafy vegetables, pulses and milk products are rich in calcium and vitamins. leafy vegetables pulses milk products Good posture: We should always sit straight in the upright posture to keep our bones strong. Exercise and play: Playing and exercising regularly keeps our bones strong and healthy. WHAT IS A FRACTURE? Sometimes bones may get hurt because of good and bad postures accidents or a bad fall on the playground. In such cases, the bones may crack or break. This crack or break is called a fracture. How can we know if there is a fracture in our bone? For this, an x-ray picture is taken. It helps the doctor to see the fracture in the bones. The doctor will then put a plaster around the fracture affected area. The plaster keeps the bone in the correct position and helps in healing. 14 7/28/2023 3:43:03 PM Science_G3_TB_Part1.indb 14

AB CD E plaster plaster helps to heal the fracture Amazing Facts The smallest bone in our body is found in our ear. This bone is called femur the stapes. The longest bone in our body is the thigh bone or femur. Higher Order Thinking Skills (H.O.T.S.) You have learnt that humans have a skeletal system shell inside their body. Some animals have an exposed tortoise skeletal system. earthworm Have you seen a tortoise? It has a hard cover or shell on its body. The shell of a tortoise is an example of an exposed skeletal system. Make a list of animals having such shells. You must have seen many creepy-crawlies, like earthworms, around your house. Do they have skeletal systems? Connect the Dots Maths Fun An adult human has 27 bones in one hand and 30 bones in one leg. What is the total number of bones in one hand and leg? Skeletal System 15 Science_G3_TB_Part1.indb 15 7/28/2023 3:43:06 PM

Lesson Way around 5 Our 16 Neighbourhood Let Us Learn About r directions and sub-directions. u identifying directions. a mapping our neighbourhood. h the use of a compass. Think Can you help the puppy to find its way home? To reach its house, the dog needs to know where to take the correct turns. Similarly, we also need to know our way to visit places in our neighbourhood or inside our school. How do we find our way? Remembering What do we need to know before we go to any place? We should know the address and where it is located. When we tell someone how to go to a place, we give them directions. While giving directions, we use words like left, right, straight and so on. We use these words in relation to a landmark. A landmark is a well-known place in an area that can be easily seen. It can be identified from a distance. 16 7/28/2023 3:43:08 PM Science_G3_TB_Part1.indb 16

turn left turn right go straight ahead go past cross DIRECTIONS AND SUB-DIRECTIONS We also give directions using the four main directions – north (N), east (E), south (S) and west (W). There are also four sub-directions that lie between these main directions. They are north-east, north-west, south-east and south-west. north- north north- N west east west east W E south- south south- S west east Understanding How do you know Stand facing the Sun when it rises. That direction is the east. which is the north and Open your arms as shown in the picture. which is the east? Let us do an activity to Your left hand Your right hand find directions. points to points to the north. the south. These directions and sub-directions help The direction behind you is the west. us to know places in finding directions our neighbourhood. They also help us to read maps of our city, district, state and so on. Way around Our Neighbourhood 17 Science_G3_TB_Part1.indb 17 7/28/2023 3:43:10 PM

Application To read a map, you need to know the directions that you have learnt. A map is given below. It shows a house. Riya lives in this house. Her house is east-facing. She wants to go to the post office to post a letter to her friend. Let us help Riya. West South North East map Since Riya’s house is east-facing, she faces the east when she steps out. The directions are as follows: • Step out of the house and go to the road on your left. • Turn west. • Walk westward on the road. • Turn left towards south and go to the end of the road. • The post office is at the corner of the road. Is there any other way to reach the post office? Discuss with your friends. Amazing Facts An interesting way of remembering directions is: Never Eat Slimy Worms N = North, E = East, S = South, W = West 18 Science_G3_TB_Part1.indb 18 7/28/2023 3:43:11 PM

Higher Order Thinking Skills (H.O.T.S.) One more way of finding directions is to use a compass. It is a device used to find directions on the surface of the Earth. A compass has a needle which always points towards the north-south direction. It is mainly used in ships to understand the direction. compass Connect the Dots Uttar Pradesh Social Studies Fun A map of western India is shown here. Find out: Rajasthan a) state to the north of Gujarat b) state to the south of Madhya Pradesh Gujarat Madhya Pradesh N WE Maharashtra S Way around Our Neighbourhood 19 Science_G3_TB_Part1.indb 19 7/28/2023 3:43:22 PM

Lesson Forms of Water 6 Let Us Learn About R forms of water. U the water cycle. A changing water forms around us. H how salt is got from seawater. Think While going to school, Aslam saw a puddle on the road. But while coming back from school, he saw that it had dried up. How did the water disappear? puddle Remembering We hang clothes out in the Sun to dry. Why do the wet clothes dry after some time? Heat from sunlight changes the water in the clothes to water clothes hung in the Sun vapour. The water vapour moves out of the clothes and the clothes dry. We can also see water change into vapour when we boil water. When cooled, water vapour changes into water. water vapour 20 7/28/2023 3:43:25 PM Science_G3_TB_Part1.indb 20

Water has three states: solid, liquid and gas. Water has three different forms: ice, water, and water vapour. When we keep water Veinrysicdeoladfrceoenzedri,tiiot nchs acnhgaesnginetowicaetears ttoheicteem. Wpeeraftinudreicinesiidnesidthee rferefreigzeerraistvoersryalsotwh.eIce, tewmhpeenraletfut roeutinsisdideethtehereffrreigeezreartoisr,vcehraynlgoews .inIctoe,wwatheernduleefttoohuitgsihdeer ttheme preerfraigtuerrea. tor, changes into water due to the temperature being higher. ChChaannggee ccaauusesedd Iiccee CChhaannggeeccauasuesded bbyyddeeccrreeaasseeinin bbyy iinnccrreeaasseeinin tteemmppeerraattuurere tetemmppeerraattuurree Iiccee Lliiqquuiiddwwaateter r lLiqiquuiidd wwaatteerr Let us now learn about the three forms of 5w7ater. What are the differences between water, water vapour and ice? 31-Dec-21 4:37:28 PM Science Book 3.indb 57 Ice has a fixed shape. It does not flow. Water flows and does not have a shape of its own. It takes the shape of the vessel it is kept in. Water always flows downwards in nature. Water vapour has no shape. It always moves upwards and mixes with the air around. All three forms of water have no colour, smell and taste. Understanding Cooled water vapour forms When the water drops in the clouds small water droplets. These water become heavy, they fall as rain. droplets combine with other things to form clouds in the sky. Inside the During winter, clouds, water droplets combine to in some form big drops. very cold places, water During daytime, heat from the Sun changes to changes the water in water bodies into ice and snow. vapour form. The water vapour thus formed goes upwards and cools down. Rainwater gets collected in water bodies like rivers, ponds, lakes and so on. Some of the water that goes into the soil is stored underground. Thus, water changes its form and always moves from the water bodies to the clouds and back. This movement is called the water cycle. It makes water available to all living things. Forms of Water 21 Science_G3_TB_Part1.indb 21 7/28/2023 3:43:26 PM

Application We have read that clouds give us rain. What do rain clouds look like? Rain clouds are dark in colour. They are heavy and filled with water droplets. clouds rain clouds Why is it that all clouds do not come down as rain? Find out. seashore Have you ever been to a seashore? We sweat a lot when water droplets on a we are at a seashore. Do you know the reason for this? At glass of cold water seashores, the air is filled with water vapour. So, the water in our sweat does not get changed into vapour easily. Have you seen dew drops on leaves in the morning? Where do they come from? Some water vapour is always present in the air around us. It cools down when it touches any cold surface. This is the reason why we see water droplets on a glass of cold water. We learnt that wet clothes dry due to the heat from the Sun. How do wet clothes dry when we keep them indoors? In monsoon, clothes dry with difficulty. Why is it so? Amazing Facts Fog is a cloud that appears very close to the ground. 22 fog Science_G3_TB_Part1.indb 22 7/28/2023 3:43:27 PM

Higher Order Thinking Skills (H.O.T.S.) Do you know that common salt is prepared seawater collected in ponds from seawater? Seawater contains a lot of salt. So, it is unfit for drinking. This salt can be separated out. For this, the seawater is collected in open ponds. Due to the heat from the sunlight, the water changes into vapour. The salt which remains in the ponds is collected and purified to be used as common salt. Connect the Dots English Fun Anu is a drop of water. She lives in a pond. Anu was feeling very hot on a 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 the weather is hot? It follows the water cycle. Now complete the story of Anu!) Forms of Water 23 Science_G3_TB_Part1.indb 23 7/28/2023 3:43:28 PM

Inside the Lab – A Make sure you do these activities only with the help of a teacher or an adult. Activity A1: Salt from Seawater In the lesson ‘Forms of Water’, we learnt that water exists in three different forms. Let us see how we get salt from seawater due to the changing forms of water. You will need: seawater collected in ponds salt, some tap water, a saucepan, spoon, stove, tray and a black plastic sheet You need to: 1) add two cups of water to the pan. Place it on the stove. Let the water boil. 2) add salt to the hot water in the pan. Mix it well with a spoon. Salt dissolves faster in hot water. Continue adding salt until it stops dissolving in the hot water. Eventually, you will reach a point at which the salt won’t dissolve anymore, no matter how hot the water is. When you reach that point, turn the stove off and let the water cool slightly. 3) spread the black plastic sheet inside the tray. 4) pour the water from the pan into the tray. 5) keep the tray out in the Sun for two days. black plastic paper and tray (The location should be chosen wisely to prevent the setup from any external damage.) The water will change into water vapour. This will leave behind crystals of salt in the tray. They are small and shiny. Salt is prepared from seawater in a similar way. Seawater changes into water vapour during summer, leaving behind salt. 24 Science_G3_TB_Part1.indb 24 7/28/2023 3:43:29 PM

Activity A2: Create Your Compass A magnetic compass is used to detect or find out directions: north, south, east and west. It has a magnetic needle that points to the north. You can easily make your own compass. You will need: compass a bar magnet, needle, cork disc, cup/bowl/glass, pair of pliers and water You need to: 1) rub a magnet over the needle about twenty times. Always rub in the same direction. 2) cut off a small portion from one end of the cork, about 1 inch thick, making a small cork disc. This magnet 4 step should be done with the help of the teacher. 3) put the cork disc on a flat surface. Carefully needle push the needle through the side of the disc as shown in the picture. Use the pair of pliers to push the needle. This step should be done only with the help of the teacher. 4) fill a deep cup, glass or bowl with water till at least half full. 5) place the cork disk on the surface of the water. Try to keep the disc floating in the centre of the water, away from the sides of the cup. 6) place your compass on a flat surface and watch what happens. What does the needle do? When it stops moving, which direction does it point towards? Inside the Lab – A 25 Science_G3_TB_Part1.indb 25 7/28/2023 3:43:30 PM

Lesson 7 Sources of Light Our eyes help us see the things around us. But why are we unable to see in the dark? This is because our eyes can help us see things only in the presence of light. Where do we get light from? We get light from two types of sources: natural sources and artificial sources or human-made sources. Natural sources Artificial sources These sources include heavenly bodies like the Sun and the stars. These sources are made by human beings. They include electric bulbs, the Sun the stars kerosene lamps, oil lamps, candles and The Sun is the most important natural so on. source of light. kerosene oil lamp electric candle lamp bulb 26 7/28/2023 3:43:33 PM Science_G3_TB_Part1.indb 26

In the ancient times, there were no artificial sources of light. Human beings could only hunt and gather food during daytime. Then, humans discovered fire by rubbing flint. This helped them get light even after sunset. They firewood flint could also guard their caves from dangerous animals with the help of fire. Earlier, humans would burn firewood for light. As time went on, they started using oil lamps, candles and lanterns. After the discovery of electricity, humans started using artificial light sources electric lamps as a source of light. then and now Have you seen fireflies? They are insects that give out light from their bodies. Some aquatic animals like jellyfish also give out light. firefly jellyfish Which sources of light should we use? solar panels LED and CFL bulbs We should try our best to use sunlight, which is the main source of natural light on Earth. Sunlight is also the cheapest source of light. We can use solar panels to capture sunlight and convert it to electricity. This electricity can be used to light our homes at night. Artificial sources of light like electric bulbs need electricity to give out light. This electricity is limited. So, we should always use light sources which use less electricity. For example, LED bulbs, tube lights and CFL bulbs. Moreover, we should always switch off the lights when they are not in use. Some artificial sources of light cause harm to the environment. For example, kerosene lamps give out smoke. We should try to avoid the use of such harmful sources. Sources of Light 27 Science_G3_TB_Part1.indb 27 7/28/2023 3:43:38 PM

Reflection Time! 1) Nowadays, we see electric bulbs everywhere. What did people use to light up their homes before electricity was discovered? 2) Why do we need to switch off lights when they are not in use? 3) What kind of work can you only do with a good source of light? 4) How is your health affected if you read or do stitching in a dimly lit room? 28 7/28/2023 3:43:39 PM Science_G3_TB_Part1.indb 28