The atomic radill of alkali meals (M) lie in the order `Li lt Na lt K lt Rb,` but the radii of `M^(+)` ions in aqueous solution lie in the reverse order `Li^(+) gt Na^(+) gt Rb^(+).` What is the reason for this reverse order (on going from Li to Rb)

Options

A. Gradual increases in ionisation energy
B. Increasing weakness of the metallic bond
C. Increasing electropositive character
D. Decreasing degree of hydration

Answer

D

Explanation

Small atomic size has more tendency of hydration, so as the size increases tendency for hydration also decreases.