Ncert Exercises & Solutions

20. In which of the following options order of arrangement does not agree with the variation of property indicated against it?

(a) Al³⁺<Mg²⁺<Na⁺<F^- (Increasing ionic size)

(b) B<C<N

(d) Li<Na<K

(b, c)

Due to greater stability of the half filled electronic configuration of nitrogen, its ionisation enthalpy is higher than that of oxygen. Thus, option (b) is incorrect.

Due to stronger electron-electron repulsions in the small size of fluorine the negative electron gain enthalpy of fluorine is lower than that of chlorine. Hence, option (c) is incorrect.

NEET Information

courses

Company

Botany Questions

Chemistry Questions

Physics Questions

Zoology Questions