Which of the following statements are “true” ?
(a) Water vapour is present in air only during the monsoon. ( )
(b) Water evaporates into air from oceans, rivers and lakes but not from the soil.( )
(c) The process of water changing into its vapour, is called evaporation.( )
(d) The evaporation of water takes place only in sunlight.( )
(e) Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.( )
(a) False
It is false because water vapours are present in air in every season.
(b) False
Due to high temperature, water evaporates from soil also.
(c) True
This statement is true because conversion of water into vapours is called evaporation.
(d) False
Evaporation of water also occurs on heating.
(e) True
This statement is correct because condensation is the process of conversion of water vapours into tiny droplets of water.
Draw (a) a leaf, (b) a taproot and (c) a flower, you have studied for Table 7.3.
You are given an iron strip. How will you make it into a magnet?
Name two foods each rich in:
(a) Fats
(b) Starch
(c) Dietary fibre
(d) Protein
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
Tick (√) the statements that are correct.
(a) By eating rice alone, we can fulfill nutritional requirement of our body. ( )
(b) Deficiency diseases can be prevented by eating a balanced diet. ( )
(c) Balanced diet for the body should contain a variety of food items. ( )
(d) Meat alone is sufficient to provide all nutrients to the body. ( )
List all items known to you that float on water. Check and see if they will float on an oil or kerosene.
Name the part of the plant which produces its food. Name this process.
Why can a pace or a footstep not be used as a standard unit of length?
Given below are the names of some objects and materials:
Water, basket ball, orange, sugar, globe, apple and earthen pitcher Group them as:
(a) Round shaped and other shapes
(b) Eatables and non eatables
Name two items that are made from coconut fibre.
Name two flowers, each with joined and separated sepals.
Can you find a plant in your house or in your neighborhood, which has a long but a weak stem? Write its name. In which category would you classify it?
True or false?
(a) A mixture of milk and water can be separated by filtration.
(b) A mixture of powdered salt and sugar can be separated by the process of winnowing. (c) Separation of sugar from tea can be done with filtration.
(d) Grain and husk can be separated with the process of decantation.
Explain the process of making yarn from fibre.
How will you show that air is dissolved in water?
Lemonade is prepared by mixing lemon juice and sugar in water. You wish to add ice to cool it. Should you add ice to the lemonade before or after dissolving
sugar? In which case would it be possible to dissolve more sugar?
Write the names of the parts of a flower.
Would the bulb glow in the circuit shown in Fig. 12.15?
Indicate true (T) and false (F) among the following sentences.
(a) The movement and locomotion of all animals is exactly the same. ( )
(b) The cartilages are harder than bones. ( )
(c) The finger bones do not have joints. ( )
(d) The fore arm has two bones. ( )
(e) Cockroaches have an outer skeleton. ( )
Name five plants and their parts that we eat.