3. Fill in the blanks in the following statements:
(a) When carbon dioxide is passed through lime water, it turns milky due to the formation of _________.
(b) The chemical name of baking soda is _________.
(c) Two methods by which rusting of iron can be prevented are _________ and _________.
(d) Changes in which only _________ properties of a substance change are called physical changes.
(e) Changes in which new substances are formed are called _________ changes.
(a) When carbon dioxide is passed through lime water, it turns milky due to the formation of calcium carbonate.
(b) The chemical name of baking soda is sodium hydrogen carbonate.
(c) Two methods by which rusting of iron can be prevented are galvanization and painting.
(d) Changes in which only physical properties of a substance change are called physical changes.
(e) Changes in which new substances are formed are called chemical changes.
1 calcium carbonate
2 sodium hidrogen carbonate
3 galvanisation and painting
4 physical change
5 chemical change
ANS 3} a] calcium carbonate
b] sodium bicarbonate
c] greasing and galvanization
d] physical
e] chemical