Question

Of the following, which element has the highest first ionization energy?

F

B

Li

N

Answer 1

Ionization energy:

The miniumum amount of energy required to remove an electron from outermost orbit of an isolated gaseous atom is called ionization energy.

Higher the electronegativity and smaller the size of element larger will be the force of atraction between the electrons and the nucleus and consequently higher will be the ionization energy.

When we move across a period the number of shell remains constant while in each step the nuclear charge increase. So, the attraction force between the nucleus and the electrons increase in each step. So, the ionization energy increase when we move across a period from left to right.

So, among the given set of elements F will have the highest ionization energy because it is the most right to all the other three.