Classify the following as physical or chemical changes:
The following is the classification into physical and chemical change:
Physical change | Chemical change |
i. Cutting the trees | i. Rusting of almirah |
ii. Boiling of water to form steam | ii. Passing of electric current through water, and water breaking into hydrogen and oxygen gases |
iii. Melting of butter in a pan | iii. Burning of paper and wood |
iv. Making a fruit salad with raw fruits | |
v. Dissolving common salt in water |
Which of the following are chemical changes?
(a) Growth of a plant
(b) Rusting of iron
(c) Mixing of iron filings and sand
(d) Cooking of food
(e) Digestion of food
(f) Freezing of water
(g) Burning of candle
Classify the following into elements, compounds and mixtures.
(a) Sodium
(b) Soil
(c) Sugar solution
(d) Silver
(e) Calcium carbonate
(f) Tin
(g) Silicon
(h) Coal
(i) Air
(j) Soap
(k) Methane
(l) Carbon dioxide
(m) Blood.
Which of the following will show the “Tyndall effect”?
(a) Salt solution
(b) Milk
(c) Copper sulphate solution
(d) Starch solution.
Identify the solutions among the following mixtures.
(a) Soil
(b) Sea water
(c) Air
(d) Coal
(e) Soda water
Which of the following materials fall into the category of "pure substance"?
(a) Ice
(b) Milk
(c) Iron
(d) Hydrochloric acid
(e) Calcium oxide
(f) Mercury
(g) Brick
(e) Wood
(f) Air.