Question

Why beryllium electron affinity is less compared to lithium?

Answer 1

Answer:

The electron added in the Lithium goes into the 2s subshell which being close to the nucleus experiences greater electrostatic force of attraction compared to the one going into the 2p subshell of the Boron atom which is relatively more diffused( spread out in space ) ............

Answer 2

Explanation:

The electron being added to lithium is going into the 2p shell which is relatively much closer to the nucleus (and has greater electrostatic attraction), while that going into boron enters the 2p shell, which is relatively more diffuse.