Two cylinders A and B are formed by folding a rectangular sheet of
dimensions 20 cm × 10 cm along its length and also along its breadth
respectively. Then volume of A is ________ of volume of B.
When baking soda is mixed with lemon juice, bubbles are formed with
the evolution of a gas. What type of change is it? Explain.
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.
State whether the following statements are true or false. In case a
statement is false, write the corrected statement in your notebook.
(a) Cutting a log of wood into pieces is a chemical change. (True/False)
(b) Formation of manure from leaves is a physical change. (True/False)
(c) Iron pipes coated with zinc do not get rusted easily. (True/False)
(d) Iron and rust are the same substances. (True/False)
(e) Condensation of steam is not a chemical change. (True/False)
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