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

Question

Responses

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

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.

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.

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

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 compared to magnesium (Mg) because chlorine is one electron short of a full outer shell (it has 7 valence electrons), making its outer electrons more tightly bound and therefore requiring more energy to remove one. In contrast, magnesium (Mg) has 2 valence electrons and a lower ionization energy since it is easier to remove these 2 electrons to achieve the stable electron configuration of neon.