The second ionization energies of Li, Be, B and C are in the order

Options

A. `Li gt C gt B gt Be`
B. `Li gt B gt C gt Be`
C. `B gt C gt Be gt Li`
D. `Be gt C gt B gt Li`

Answer

B

Explanation

The configurations of atoms and ions after removing one electron are :
`{:(Li, :, 1s ^(2) 2s ^(1), Li ^(+) , :, 1s ^(2)),(Be, :, 1s ^(2) 2s ^(2), Be ^(+), :, 1s ^(2) 2s ^(1)),(B ,:, 1s ^(2) 2s ^(2) 2p ^(1), B ^(+), :, 1s ^(2) 2s ^(2)), (C , :, 1s ^(2) 2s ^(2) 2p ^(2) , C ^(+), :, 1s ^(2) 2s ^(2) 2p ^(1)):}`
Hence the order of `IE_(2)` is `Li gt B gt C gt ` Be