Question

Below are the ionization energies for magnesium, $Mg$

Electron	Ionization Energy $\left(kJ/mol\right)$
$1$	$737.7$
$2$	$1450.7$
$3$	$7732.7$
$4$	$10542.5$
$5$	$13630$
$6$	$18020$
$7$	$21711$
$8$	$25661$
$9$	$31653$
$10$	$35458$
$11$	$169988$
$12$	$189367.7$

Based on the ionization energies provided, how could you determine the number of electron energy levels in neutral atom of Magnesium?

• A. Periodic, significant increases in the ionization energy indicate there are $3$ energy levels in a neutral atom of Mg.
• B. Periodic, significant increases in the ionization energy indicate there are $4$ energy levels in a neutral atom of Mg.
• C. Periodic, significant increases in the ionization energy indicate there are $12$ energy levels in a neutral atom of Mg.
• D. Ionization energies cannot be used to determine the number of levels in a neutral atom of Mg.

Answer 1

The correct option is A Periodic, significant increases in the ionization energy indicate there are $3$ energy levels in a neutral atom of Mg.

Due to attainment of Nobel gas configuration at ${1s}^2,{2s}^2,2p^6$ level, there is an excessive rise in I.E. So, there are $3$ energy levels for $Mg$.

Steep rise: from $2\to 3,10\to 11\}$so three energy level.