The element having lowest ionisation energy among the following is

Options

A. `1s^(2),2s^(2),2p^(3)`
B. `1s^(2),2s^(2),2p^(6),3s^(1)`
C. `1s^(2),2s^(2),2p^(6)`
D. `1s^(2),2s^(2)2p^(5)`

Answer

b

Explanation

`1s^(2) ,2s^(2) 2p^(6)3s^(2)`1 , (Na) having lowes ionisation energy among the option
`:'` Removed of electrons is eacier in the order of shell is ` 4 gt 3 gt 2 gt 1`.