Which of the following is an alloy?

Which gas is the lightest in weight?

State whether the following statement is true or false:
Non-metals react with acids to produce a salt and hydrogen gas.

Give the formulae of the stable binary compounds that would be formed by the combination of the following pairs of elements:
$(a)$ $Mg$ and $N_{2}$
$(b)$ $Li$ and $O_{2}$
$(c)$ $Al$ and $Cl_{2}$
$(d)$ $K$ and $O_{2}$

What is the shape of rhombic sulphur?

Which non-metal element possesses luster?