Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:

Air, water, a piece of rock, a sheet of aluminium, a mirror, a wooden board, a sheet of polythene, a CD, smoke, a sheet of plane glass, fog, a piece of red hot
iron, an umbrella, a lighted fluorescent tube, a wall, a sheet of carbon paper, the flame of a gas burner, a sheet of cardboard, a lighted torch, a sheet of cellophane, a wire mesh, kerosene stove, sun, firefly, moon.

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.

Fill up the blanks in the following:
(a) The process of changing of water into its vapour is called _________________.
(b) The process of changing water vapour into water is called _________________.
(c) No rainfall for a year or more may lead to _________________ in that region.
(d) Excessive rains may cause _________________.

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. ( )

Would the bulb glow after completing the circuit shown in Fig. 12.14 if instead of safety pin we use an eraser?

State whether the statements given below are True or False.
(i) Stone is transparent, while glass is opaque.
(ii) A notebook has lustre while eraser does not.
(iii) Chalk dissolves in water.
(iv) A piece of wood floats on water.                                                                                                                                                                                                (v) Sugar does not dissolve in water.
(vi) Oil mixes with water.
(vii) Sand settles down in water.
(viii) Vinegar dissolves in water.

Name two items that are made from coconut fibre.

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?

(a)Collect different kinds of packaging material. What was the purpose for which each one was used? Discuss in groups.
(b) Give an example in which packaging could have been reduced?
(c) Write a story on how packaging increases the amount of garbage.

Name the part of the plant which produces its food. Name this process.

While measuring the length of a knitting needle, the reading of the scale at one end is 3.0 cm and at the other end is 33.1 cm. What is the length of the needle?

Find the odd one out from the following:

a) Chair, Bed, Table, Baby, Cupboard
b) Rose, Jasmine, Boat, Marigold, Lotus
c) Aluminium, Iron, Copper, Silver, Sand
d) Sugar, Salt, Sand, Copper sulphate