The first ionization enthalpy of which given element is higher than the first ionization enthalpy of magnesium?
Lithium
Beryllium
Sodium
Calcium
The first ionization enthalpy of magnesium is lower than the first ionization enthalpy of Beryllium because belongs to same group, and down the group ionization energy decreases so the first ionization enthalpy of magnesium is lower than the first ionization enthalpy of Beryllium (Be).
Lithium sodium anyhow belongs to Group 1 however they are having low ionization potentials than these because they have only one valence shell electron.