Which has a higher ionization energy: chlorine (Cl) or magnesium (Mg)? Why? Select the best answer.(1 point)

Question

Responses

Mg; magnesium has more valence electrons than chlorine.
Mg; magnesium has more valence electrons than chlorine.

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

Cl; it takes less energy to add an electron to a valence shell that is nearly full.
Cl; it takes less energy to add an electron to a valence shell that is nearly full.

Mg; it takes more energy to pull two electrons away from magnesium(Mg) than it does to take them from chlorine(Cl).

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 has a higher ionization energy than magnesium because chlorine is one electron short of having a complete valence shell, making its electrons more tightly held and requiring more energy to remove an electron. In contrast, magnesium has three electrons in its outer shell and is less tightly bound compared to chlorine, hence it has a lower ionization energy.