Metallic oxides of zinc, magnesium and copper were heated with the following metals.

Metal	Zinc	Magnesium	Copper
Zinc oxide	-	-	-
Magnesium oxide	-	-	-
Copper oxide	-	-	-

In which cases will you find displacement reactions taking place ?

Give an example of a metal which

$(i)$ is a liquid at room temperature.

$(ii)$ can be easily cut with a knife.

$(iii)$ is the best conductor of heat.

$(iv)$ is a poor conduct of heat.

Give reasons : Platinum, gold and silver are used to make jewellery.

State two ways to prevent the rusting of iron.

What are alloys ?

Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).