Q.6 Give reasons for the following.
(a) Aluminium foils are used to wrap food items.
(b) Immersion rods for heating liquids are made up of metallic substances.
(c) Copper cannot displace zinc from its salt solution.
(d) Sodium and potassium are stored in kerosene

a) Aluminium is a metal which shows malleability and thus can be drawn into thin sheets. Hence aluminium foils are used to wrap food items.

b) Immersion rods for heating liquids are made up of metallic substances because metals are good conductors of heat and electricity. Metals have free electrons that can carry heat and current from one point to another.

c) Copper cannot displace zinc from its salt solution because copper is less reactive than zinc so it cannot displace zinc.

d) Sodium and potassium are highly reactive metals which reacts immediately with atmospheric oxygen, once it comes in contact with air. To avoid any hazardous situation sodium and potassium are stored in kerosene.