Which one of the following is expected to have largest size?

Options

A. `F^(-)`
B. `O^(-2)`
C. `Al^(+3)`
D. `N^(-3)`

Answer

D

Explanation

Due to having three electrons atomic size increases.
`F^(-) = 9 + 1= 10` electrons , `O^(-2) = 8 + 2 = 10` electrons
`Al^(+3) = 13 - 3 = 10`electrons , `N^(3-) = 7 + 3 = 10e^(-)`.
Because electrostatic force between nucleus and `e^(-)` cloud is least in nitrogen.