Question

There are four elements p, q , r and s having atomic number $Z-1,Z,Z+1,Z+2$ respectively. If the element q is an inert gas, select the correct statements from following statements:
(i) p has most negative electron gain enthalpy in the respective period
(ii) r is an alkali metal
(iii) s exists in +2 oxidation states

• A. (i) and (ii) only
• B. (ii) and (iii) only
• C. (i) and (iii) only
• D. (i), (ii) and (iii)

Answer 1

The correct option is D (i), (ii) and (iii)

Since, q is an inert element i.e noble gas. So, p, r and s have atomic number $Z-1,Z+1,Z+2$ and they should belong to halogen, alkali metal and alkaline earth metal respectively.
As halogen has one electron less than stable noble gas configuration it has greater tendency to accept an additional electron forming anion. Alkaline earth metals having valence shell electronic configuration $n{s}^2$ exists in +2 oxidation state.