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 ?
(d) What would be the nature (acidic/basic) of oxides formed ?
(e) Locate the position of the element in the modern table.

Explanation

(a) Element X which is a yellow solid at room temperature, shows catenation and alltropy is sulphur (S). It forms two oxides `SO_(2) and SO_(3)` which are also formed during thermal decomposition of ferrous sulphate crystals and are the major air pollutants
(b) Atomic number of S = 16
Its electronic configuration is `underset(2)(K)underset(8)(L)underset(6)(M)`
(c) `underset("Ferrous sulphate")(2FeSO_(2))overset("Heat")(rarr)underset("Ferric oxide")(Fe_(2)O_(3))+underset("Sulphur dioxide")(SO_(2))+underset("Sulphur trixode")(SO_(3))`
Both `SO_(2)` and `SO_(3)` are major air pollutants
(d) Since, sulphur is a non-metal, therefore, both `SO_(2)` and `SO_(3)` are acidic oxides (non-metals form acidic oxides). They dissolve in water to form the corresponding acids
`underset("Sulphur dioxide")(SO_(2))+ underset("Water")(H_(2)O)rarr underset("Sulphurous acid")(H_(2)SO_(3)),underset("Sulphur trioxide")(SO_(3))+underset("Water")(H_(2)O)rarrunderset("Sulphuric acid")(H_(2)SO_(4))`
(e) Since, sulphur contains six valence electrons, therefore, it lies in group `6 + 10 =16`. Further, since atomic number of sulphur (S) is 16, electronic configuration is `underset(2)(K)underset(8)(L)underset(6)(M)`
So, it lies in `3^(rd)` period.