Question

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

• A. Li < B < Be < C
• B. Li > Be > B < C
• C. Li > Be > B > C
• D. Li < Be > B > C

Answer 1

The correct option is A Li < B < Be < C

As we go from left to right in a period, the ionization potential increases. Be and B are exceptions.

As Be has electronic configuration $1s^{2}2s^2$ and B has $1s^{2}2s^{2}2p^1$, it's easy to remove electron from boron than beryllium.

So, option A is correct.