Question

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

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

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).

Answer 1

The correct response 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 has seven valence electrons and is close to having a full octet (8 electrons), making it more energetically unfavorable to remove an electron. In contrast, magnesium has two valence electrons and is located further away from achieving a stable electron configuration. Therefore, it takes more energy to remove an electron from chlorine than from magnesium.