Rukhsana Kanwar

Chapter no. 11: AIR, WATER AND WEATHER Topic: Question answers Q 1. With a neat diagram write a note on sea breeze. Ans. During the day, the land gets warmer faster than the water. The air above the land too becomes warm and rises up. The cool air from the sea moves in towards the land and takes its place. This is called sea breeze. (dig pg no. 86) Q 2. Define weather. Ans. Weather is the state of atmosphere of a place at a particular time in relation to heat, cloudiness, dryness, sunshine, wind and rain. The weather can be hot, cold, dry, windy, rainy. Q 3. How does growth of crops depend on weather? Ans. Weather should be suitable for a proper growth of crops. Sudden changes in weather damage the crops. Like this: 1. Lack of rain and long hot dry periods destroy the crops. 2. In storm, the fruits fall off. 3. Hail stones damage the blossoms, fruits, ears of grains etc. Q 4. What are the factors affecting evaporation? Ans. There are three factors affecting the rate of evaporation: 1. Temperature: Higher the temperature faster is the rate of evaporation. Wet clothes dry faster in the hot sun than in the shade. 2. Wind: Wet clothes will dry faster under a fan blowing air on them than the clothes which are kept for drying in still air. 3. Surface area: A wet cloth which is spread out will dry faster than a wet cloth, which is folded because a larger area is exposed for drying.[dig.pg no 88] Q 5. What is hail? Ans. When it is cold the rain drops freeze and turn into ice. This is called hail. Q 6. How do evaporation and condensation take place in nature? Ans. Evaporation and condensation take place in nature too. Evaporation: Water on the surface of rivers, pons, lakes, and oceans gets heated up by the heat of sun and evaporates. It rises up in the air. Condensation: As the water vapour reaches the upper part of atmosphere, it cools downs and condenses as tiny droplets of water to form cloud. Rain: The water droplets in the clouds further condense to form bigger drops of water which come down to the Earth as rain. The rain water flows down to fill the water bodies. This cycle of evaporation, condensation and subsequent return of water to the surface of the Earth is called water cycle. [dig. Pg no 90] Q 7. Name the forms that water vapours takes on cooling. Ans. Water vapour takes different forms on cooling: 1. Hail: When it is cold rain drops freeze into ice, this is hail. 2. Dew: When water vapour condenses on cold objects like flowers, leaves and window panes dew is formed. 3. Frost: In extreme cold dew freezes into white crystals called frost. 4. Fog: In winter, water vapour in the air condenses on dust particles and forms a cloud above the ground called fog. 5. Snowflakes: When water vapour cools suddenly, it freezes into snowflakes. Q 8. What is the difference between Dew and Frost? [dig. Pg no 90,91] DEW FROST In winter, when water vapour In extreme cold dew freezes into condenses on cold object like white crystals called frost. Leaves, windowpanes and Flowers dew is formed NOTE: A and C part from exercise do it on your book. Chapter no. 10: FORCE, WORK AND ENERGY Topic: Question answers Q 1. Define force. Ans. Push and pull is a force. Example: when we throw a ball or hit a ball we use force. Q 2. Name any two types of forces. Ans. 1.Gravitational force [dig.pg no 78] 2. Frictional force Q 3. Draw and name any two simple machines. Ans. 1. Pulley 2. Lever (dig pg no. 79) Q 4. When is work is said to be done? Ans. Work is done when an object is moved through a distance by using force. (work is done only when the body moves). Example: When we kick a ball it moves from its position so work is done. Q 5. Write a short note on solar energy. Ans. Solar energy: Solar means sun. The energy that we get from the sun is called solar energy. Sun: We get heat and light from the sun. Advantages of solar energy: 1. Green plants make food by using this energy. 2. Plants, animals and human beings use this food to get energy. 3. Wood and coal have stored solar energy. Uses: Solar energy is used in solar heater and solar cooker. (dig pg no. 80) Q 6. Name two devices which use solar energy. Ans. 1. Solar Heater 2. Solar cooker. [dig.pg no 81] Q 7. Which type of energy is used to fly a kite? Ans. Wind energy. Chapter no. 6: PLANTS --- MAKING FOOD Topic: Question answers Q 1. Draw a diagram and label the parts of a leaf. Ans. Diagram on page no. 41 Q 2. What is the function of veins in a leaf? Ans. Veins: Veins are small tubes. Function: Veins take water from stem and supply it to all parts of the leaf. Q 3. Write a short note on stomata in the leaf. Ans. Stomata: The leaf has minute pores called stomata. There are more stomata on the lower surface of the leaf. Air enters and passes through the leaf through these stomata. Water vapours are too released through the stomata.[dig.pg no 42] Q 4. What does a plant require to make food? Ans. A plant requires sunlight, carbon dioxide and water to make food. Q 5. Does photosynthesis take place 24 hours of the day? Why? Ans. No, photosynthesis does not take place 24 hours of the day because at night there is no sunlight, which is necessary for making food. Q 6. What food does a plant prepare? Ans. In leaves, chlorophyll uses sunlight and changes water and carbon dioxide into sugar. This sugar is plant’s food.[dig pg no 43] Q 7. With a neat labelled diagram show how plants and animals depend on each other for the gases they need. Ans. Diagram on page no. 45 Exercise;[part A,B and task on book] Chapter No. 1 OUR FOOD        Words Meanings. Repairing Wear and tear Nutrients Organ Physical work Protect Digest To mend Worn out Providing nourishment Body part Manual work Keep safe Dissolve Answer these questions shortly. 1. What are nutrients? Ans. Food contains different substances which are useful to our body, these substances are called nutrients. These nutrients are necessary for life and growth, for example proteins, fats, carbohydrates, etc. (Diagram on Page # 2 and 3) 2. Write two foods that are rich in carbohydrates. Ans. Potato and rice. 3. Name any two minerals which are needed in small amounts. Ans. Iodine and fluoride. 4. What is a balanced diet? Ans. The diet that provides all the nutrients in the right amount is a balanced diet. It keeps us fit and healthy. (Diagram on Page # 4) 5. Why do we cook food? Ans. We cook food because cooking makes food soft, tasty and easy to digest. It also kills germs. Give reasons. i. Proteins should be included in our daily diet. Proteins are the body building food. They help the body to build muscles, organs and blood. They also help to repair the wear and tear of the body. ii. Vitamins and minerals are called “Protective food”. They help our body to fight against diseases and keep us healthy, that’s why they are called “Protective food”. iii. Fruits and vegetables should be washed before eating. Fruits and vegetables carry dust and mud which carry germs that cause diseases. They are also sprayed with chemicals to protect them from diseases, so fruits and vegetables should be washed before eating. iv. Food should be cooked in just enough water. Food should be cooked in just enough water because extra water contains nutrients. If extra water is thrown away, these nutrients are also lost. EXERCISE PAGE # 7, PART A & B ARE DONE ON BOOK. Chapter No. 2 TEETH AND DIGESTION          Words Meanings Swallow Digestion Gums Alike Soluble Appear Absorb Blood vessels Saliva To consume, eat up Breakdown of food into simple food The flesh around the teeth Same Able to be dissolved Become visible Take in Tubular structures that carry blood A watery secretion in the mouth Answer these questions. 1. Name the different types of teeth and their functions. Ans. Types of teeth: There are following types of teeth: i. Incisors ii. Canines iii. Pre-molars and Molars. i. Incisors: Functions: Front four teeth in each jaw Cutting of food ii. Canines: Function: Two pointed teeth, one on each side of the incisors. Grip and tear the food. iii. Pre-molars and Molars: The remaining flat teeth Function: Grinding and chewing (Diagram on Page # 10) 2. Draw and label the structure of a tooth. (Diagram on Page # 11) 3. What causes tooth decay? Ans. Many types of germs live in the mouth, they feed on leftover food particles and give out a substance called acid. The acid damages the teeth and slowly a hole called ” cavity ” forms. This hole gets deeper and causes the tooth decay. 4. How should you take care of your teeth? i. Brush your teeth clean and properly. ii. Rinse your mouth every meal. iii. Do not eat sticky food and sweets. iv. Do not forget to clean your tongue. v. Eat food that contains calcium and vitamins. 5. What is meant by digestion of food? Ans. The process of breaking down of food into simpler forms that can dissolve in the blood and be carried to all parts of our body is called digestion of food. 6. Draw a diagram and write what happens to the food in the stomach. Ans. Stomach is a muscular bag. In the stomach food is churned and digestive juices are added. The food turns into semi-liquid mixture. Here proteins are broken into simpler forms. 7. What is the main role of large intestine? Ans. The large intestine contains undigested food. Here water is absorbed from the undigested food, leftover is thrown out of the body by anus. EXERCISE PAGE # 15 & 16, PART A, B & C ARE DONE ON THE BOOK. Chapter No. 3 CLOTHES AND FIBRES Topic: Words meanings WORDS MEANINGS Fibre Thread of material Rot Process to separate fibres Twisted Wound spirally Loom Weaving machine Wrinkle A fold on a cloth Shear To cut off Dyed Coloured Answer these questions in short. Q 1. How do you get coloured, printed cotton cloth? Ans. We get cotton from cotton plants. These cotton bolls have thin fibres. Fibres are spun into thread yarn. Yarn is woven to make cloth. Cloth is dyed with colours or printed. (dig pg no. 18) Q 2. How do we get wool? Ans. We get wool from thick coat of hair on the skin of animals like goats and camels. Q 3. How is silk cloth made? Ans. Silk cloth is made from silk worm. The silk worms spin a silky thread and wrap it around their bodies. This silky covering is called cocoon. The cocoons are put into hot water and unwind the thread carefully. The thread is woven into silk cloth. (dig pg no. 20) Q 4. How do we get fibres from the flax plant? Ans. The stem of flax plants are allowed rot than they are beaten to separate the long fibres. Fibres are woven into cloth. Q 5. What are the differences between natural fibres and synthetic fibres? Natural Fibres Synthetic Fibres Fibres that we get from plants Fibres that we get from different And animals are called natural chemicals in factories are called fibres. synthetic fibres. Example: Cotton, linen, silk, Example: Rayon, nylon, polyester. Wool. Note: Part A (Page # 22) and B (Page # 23) are done on books. Chapter No. 4 HOUSES ALL AROUND Words Meaning Climate Weather condition of a place Construction To build Slope Steep downward Damage To harm Twigs A small thin branch of tree Budget A plan for using money Answer these questions shortly. 1. What are the advantages of having a thatched roof? Ans. Mud and clay houses with thatched roof remain cool in summer and warm in winter. 2. Name any five building materials used in making a low cost temporary house. Ans. Mud, Clay, Sand, Straw, Twigs, Gravel 3. Name any five building materials used in making a big permanent house. Ans. Granite, Slate, Marble, Cement, Metal. 4. Why is glass used as a building material? Ans. Glass is used as a building material because of its ability to let light in and keep dust and insects away. 5. Name the various people who work to build a house. Ans. Architect, Engineer, Mason, Carpenter, Fabricator, Plumber, Electrician, Painter. PART A & B (PAGE # 30) AND TASK (PAGE # 31) ARE DONE ON BOOK Chapter No. 5 SOLIDS, LIQUIDS AND GASES      Words Soluble Fluids Solution Vessel Insoluble Meanings That can be dissolved That can flow Mixture of solute and solvent Long narrow tube That cannot be dissolved Answer these questions in a sentence. 1. What is matter? Ans. Anything that has weight and occupies space, is called matter. For example, plastic, glass, wood, metal, etc. 2. Why do solids have a definite shape and size? Ans. In solids, molecules are closely packed. They do not have space between them to move, so they have definite shape and size. 3. How is a gas able to spread in all directions? Ans. In gas, molecules are far apart from each other and they have lot of space between them, so gas spreads in all directions due to free movement of molecules. 4. Do molecules in a liquid have more space between them than in solids? Ans. Yes, molecules in a liquid have more space between them than in solids. 5. What is solubility? Ans. The ability of a solute to dissolve in a solvent is known as solubility. For example, when sugar (solute) is dissolved in water (solvent) it is called its solubility. Answer these questions shortly. 1. Draw diagram showing the arrangement of molecules in solids, liquids and gases. Ans. Molecules in solid: In solids, molecules are closely packed so they have definite, shape, size and volume. (Diagram Page # 33) Molecules in liquid: In liquids, molecules are not closely packed, there is some space between them, so they do not have definite shape but they have definite volume. (Diagram Page # 33) Molecules in gas: In gas, molecules are far apart and can move freely, so they do not have definite shape nor definite volume. (Diagram Page # 34) 2. Write the differences between solids and liquids. Ans. SOLIDS LIQUIDS  In solids, molecules are In liquids, molecules are not closely packed. closely packed.  They do not have space They have some space between them. between them.  They have definite shape, They do not have definite shape size and volume. but they have definite volume. EXAMPLE  Table, chair, ball, etc. Milk, oil, water, etc. 3. How can you change ice into steam? Ans. Ice can be changed into steam by heating it. When ice is heated it melts and changes into water. If heated more, the water changes into steam. NOTE PART A (PAGE # 38), PART B (PAGE # 39) ARE DONE ON BOOK