Question

The order of decreasing ionisation enthalpy in alkali metals is
(a) Na > Li > K > Rb
(b) Rb < Na < K < Li
(c) Li > Na > K > Rb
(d) K < Li < Na < Rb

Answer 1

(c)

Because as we go down the group the radius of the orbital increases and the ionisation enthalpy will be redusing down the group.

Answer 2

Answer:

(c)

Li > Na > K > Rb

hope it helps u !!