Question

When the size of an atom decreases, the ionization enthalpy will .

• A. increase
• B. remains same
• C. decrease

Answer 1

The correct option is A increase

As the size of an atom decreases, the force of attraction increases which will result in the increase of ionization enthalpy.

For example, in an aluminium atom, when you remove an electron from $A{l}^{+1}$ it becomes $A{l}^{2+}$, the size of an atom decreases. Therefore, the force of attraction between the nucleus and electron will increase and hence, the ionization enthalpy increases.