Give reasons for the following:
(a) Metals can be given different shapes according to our needs.
(b) Hydrogen is not evolved when a metal reacts with nitric acid.
Reasons:
(a) Metals can be given different shapes according to our needs because metals are malleable (i.e., metals can be hammered into thin sheets) and ductile (i.e., metals can be drawn into thin wires).
(b) Hydrogen is not evolved when a metal reacts with nitric acid because nitric acid is a strong oxidising agent. So, as soon as hydrogen gas is formed in the reaction between a metal and dilute nitric acid, the nitric acid oxidises this hydrogen to water.