Question

I. Atomic and ionic radii of group- $16$ elements decrease from top to bottom.
II. Ionisation enthalpy decreases down the group-$16$.
III. Oxygen has less negative electron gain enthalpy than sulphur.
The correct statement(s) is/are

• A. Only I
• B. Only II
• C. Both II and III
• D. All of these

Answer 1

Answer: (C)

The elements of group-$16$ have six electrons in the outermost shell and have $n{s}^{2}n{p}^4$ general electronic configuration. Due to increase in the number of shells, atomic and ionic radii increase from top to bottom in the group. However, the size of $O$-atom is exceptionally small.I onisation enthalpy decreases down the group. It is due to increase in size. However, the elements of this group have lower ionisation enthalpy values as compared to those of group-$15$ in the corresponding periods. This is due to the fact that group-$15$ elements have extra stable half-filled $p$-orbitals electronic configuration.