The decreasing order of the ionization potential of the following elements is

Options

A. `Ne gt Cl gt P gt S gt Al gt Mg`
B. `Ne gt Cl gt P gt S gt Mg gt Al`
C. `Ne gt Cl gt S gt P gt Mg gt Al`
D. `Ne gt Cl gt S gt P gt Al gt Mg`

Answer

B

Explanation

`[Ne] = 1s^2 2s^2 2p^6`
`Cl = 1s^2 2s^2 2p^6 , 3s^2 3p^5`
P = 1s^2, 2s^2 2p^2, 3s^2 3p^3`Half filled orbital
`S = 1s^2 , 2s^2 2p^6, 3s^2 3p^4`

Neon have completely filled orbital hence not a easy manner to remove the `e^(-)` from the outer most shell.
Al can remove the `e^(-)` easily than Mg to form stable orbital. Hence the ionization energy order will be
`Ne gt Cl gt P gtS gt Mg gt Al`.