The following qualitative plots depict the first, second and third ionization energies (I.E.) of Mg, Al and K. Among the following, the correct match of I.E. and the metal is :

Question

TestHub · Accepted Answer

The correct option is (C): X-Mg; Y-K; Z-Al.

Magnesium (Mg) ( $[N e] 3 s^{2}$ ) loses its third electron from a stable noble gas core, resulting in an exceptionally high $I E_{3}$ ( $\sim 7733 k J / m o l$ ), which matches the highest peak X at position 3.

Potassium (K) ( $[A r] 4 s^{1}$ ) undergoes a massive jump from $I E_{1}$ to $I E_{2}$ due to its noble gas core, reaching a moderate $I E_{3}$ ( $\sim 4420 k J / m o l$ ) that matches plot Y.

Aluminum (Al) ( $[N e] 3 s^{2} 3 p^{1}$ ) loses all three valence electrons relatively easily, showing a gradual increase to a much lower $I E_{3}$ ( $\sim 2745 k J / m o l$ ), matching plot Z.

Chemistry - PERIODIC TABLE Question with Solution | TestHub

Options:

Doubts & Discussion