(a) Changes that bring formation of new substances are called ___________.

(b) Burning of wood is a __________ change.

(c) Revolution of the Earth around the Sun is a _________ change

(d) As Small plant converting into a tree is a ______________ .

(e) Melting of candle wax is a _________ change.

(f) Conversion of liquid to vapour by heating is called ___________.

(g) The changes which are controlled by man are called ________.

(a) Cooking of rice is a physical change

(b) Breaking of a china dish is a chemical change

(c) Rusting of iron is an irreversible change.

(d) Eruption of a volcano is an reversible change

(e) Conversion of solid to liquid by heating is called fusion.

(a) What are physical changes?

(e) What is freezing point?

(c) What are slow changes?

(b) What are chemical changes?

(d) Name a chemical change which takes place in the presence of (i) heat (ii) light

(1) Mention a change which is always: (i) periodic change (ii) undesirable change

(2) Write three examples each for physical and chemical changes.

(3) Explain that the burning of LPG shows both physical and chemical change

(4) Write short notes on: (i) evaporation (ii) boiling

(5) How would you say that setting of curd is a chemical change?

(1) Write any five changes which occur in everyday life

(2) Classify the changes involved in the following processes as physical and chemical changes. (i) Photosynthesis (ii) Dissolving sugar in water (iii) Burning of coal (iv) Melting wax (v) Beating aluminium to make aluminium foil (vi) Digestion of food

(3) Write any four importances of chemical changes.

Wet clothes to dry clothes

Milk to paneer

sodium chloride

Wax vapour burns into flame

Natural process