Identify the elements with the following properties and arrange them in increasing order of their reactivity:
$(a)$ An element which is a soft and reactive metal.
$(b)$ The metal which is an important constituent of limestone.
$(c)$ The metal which exists in a liquid state at room temperature.

Give reasons for the following:
$(a)$ Generally,metals are not found in their free state.
$(b)$ Metals are good conductors of heat.

Write the chemical equations for the reactions of zinc granules with:
$(a)$ Sulphuric acid
$(b)$ Hydrochloric acid
$(c)$ Aluminium chloride
$(d)$ Sodium hydroxide
$(e)$ Nitric acid

$(i)$ Arrange the following metals in the order of their decreasing activities: Aluminium, Gold, Sodium, Copper.
$(ii)$ Give the reaction of aluminium powder with manganese dioxide on heating.

Give reasons for the following:
$(i)$ Most metals conduct electricity well.
$(ii)$ The reaction of iron $(III)$ oxide,$Fe_{2}O_{3}$,with heated aluminium is used to join cracked machine parts.
$(iii)$ Sodium,potassium,and lithium are stored under oil.

An element $A$ burns with a golden yellow flame in air. It reacts with another element $B$ (atomic number $17$) to give a product $C$. An aqueous solution of product $C$ on electrolysis gives a compound $D$ and liberates hydrogen. Identify $A$,$B$,$C$,and $D$. Also,write down the equations for the reactions involved.