Which of the following pair contains species having nearly same charge density but they do not belong to same group ?

Options

A. Zr,Hf
B. `Al^(3+)`,`Be^(2+)`
C. `Fe^(2+),Fe^(3+)`
D. `Fe^(2+),Co`

Answer

B

Explanation

`Al^(3+)` and `Ba^(2+)` have nearly same charge density charge density of `Al^(3+)=3/53.5=0.056`
Charge density of `Be^(2+)=2/27=0.074`