Which has a higher ionization energy: chlorine

Question

(CI) or magnesium (Mg)? Why? Select the best answer. (1 point)
Cl; it takes much more energy to pull an
• electron away from a valence shell that is nearly full.
• Mg; magnesium has more valence
electrons than chlorine.
Mg; it takes more energy to pull two electrons away from magnesiumMg)
than it does to take them from chlorine(Cl).
O Cl; it takes less energy to add an electron to a valence shell that is nearly full.

Answer 1

The correct answer is: Cl; it takes much more energy to pull an electron away from a valence shell that is nearly full.

Chlorine (Cl) has a higher ionization energy than magnesium (Mg) because chlorine has a valence shell that is closer to being full (with 7 valence electrons) compared to magnesium, which has 2 valence electrons. It takes more energy to remove an electron from an atom with a nearly full valence shell than from an atom with fewer valence electrons.