Question

Why does the first ionization enthalpy increase as we go from left to right across a given period of the periodic table?

Answer 1

This is an account of following facts

(i) Atomic size α \(\frac{1}{I.E}\)

On moving across the period, atomic size decreases hence, ionization energy increases.

(ii) L.E. a Nuclear charge. On moving across the period, nuclear charge increases and electrons get added up in the same shell.