An element $X$ which is a yellow solid at room temperature shows catenation and allotropy. $X$ forms two oxides which are also formed during the thermal decomposition of ferrous sulphate crystals and are the major air pollutants.
$(a)$ Identify the element $X$
$(b)$ Write the electronic configuration of $X$
$(c)$ Write the balanced chemical equation for the thermal decomposition of ferrous sulphate crystals?

(N/A) The element $X$ is sulphur $(S)$, which is a yellow solid at room temperature and exhibits catenation and allotropy.
$(b)$ The atomic number of sulphur is $16$. Its electronic configuration is $2, 8, 6$ or $1s^2 2s^2 2p^6 3s^2 3p^4$.
$(c)$ The thermal decomposition of ferrous sulphate crystals $(FeSO_4 \cdot 7H_2O)$ is represented by the following balanced chemical equation:
$2FeSO_4(s) \xrightarrow{\Delta} Fe_2O_3(s) + SO_2(g) + SO_3(g)$