Question

In Boron atom, screening is due to:

• A. Electrons of K shell only
• B. All the electrons of K and L shell
• C. Two electrons of 1s and 2s each
• D. Only by electrons of L shell

Answer 1

The correct option is C Two electrons of 1s and 2s each

Screening effect : Higher is the screening effect on the outer most electrons causes less attraction from the nucleus and can be easily removed, which leads to lower value of ionisation potential.

${}_{5}B-1s^{2}2s^{2}2p^1$

So in boron screening effect is due to two electrons of 1s and 2s subshells.