$(i)$ When a metal $X$ is added to the salt solution of a metal $Y$,the following chemical reaction takes place: Metal $X +$ Salt solution of $Y \rightarrow$ Salt solution of $X +$ Metal $Y$.
$(ii)$ Mention the inference you draw regarding the reactivity of metal $X$ and $Y$ and also about the type of reaction. State the reason for your conclusions.

Study the reactions given below. State which of the following chemical reactions will take place or not,giving suitable reason for each:
$(a)$ $Zn(s) + CuSO_4(aq) \rightarrow ZnSO_4(aq) + Cu(s)$
$(b)$ $Fe(s) + ZnSO_4(aq) \rightarrow FeSO_4(aq) + Zn(s)$
$(c)$ $Zn(s) + FeSO_4(aq) \rightarrow ZnSO_4(aq) + Fe(s)$

Differentiate between metal and non-metal on the basis of their chemical properties.

Why does a magnesium ribbon start floating when it is placed in hot water?

During the reaction of some metals with dilute hydrochloric acid,following observations were made.
$(a)$ Silver metal does not show any change.
$(b)$ The temperature of the reaction mixture rises when aluminium $(Al)$ is added.
$(c)$ The reaction of sodium metal is found to be highly explosive.
$(d)$ Some bubbles of a gas are seen when lead $(Pb)$ is reacted with the acid.
Explain these observations giving suitable reasons.

Which metal catches fire when kept exposed to air?