State whether the following statement is true or false:
The elements or compounds,which occur naturally in the earth's crust,are known as minerals.

A non-metal $A$, which is the largest constituent of air, when heated with $H_2$ in a $1 : 3$ ratio in the presence of a catalyst $(Fe)$, gives a gas $B$. On heating with $O_2$, it gives an oxide $C$. If this oxide is passed into water in the presence of air, it gives an acid $D$, which acts as a strong oxidising agent.
$(a)$ Identify $A$, $B$, $C$, and $D$.
$(b)$ To which group of the periodic table does this non-metal belong?

Which of the following substances is hygroscopic?

Write the balanced chemical equation for each of the following cases:
$(a)$ Magnesium is treated with very dilute $HNO_3$.
$(b)$ Aluminium powder is added to $Fe_2O_3$.
$(c)$ Zinc sulphide is roasted.

Which salts are formed when sulfuric acid reacts with metals?

What is the number of electrons lost by a metal atom to form a positive ion called?