Which has a higher ionization energy: chlorine (Cl) or magnesium (Mg)? Why? Select the best answer.
Cl; it takes much more energy to pull an electron away from 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).
Mg; magnesium has more valence electrons than chlorine.
Cl; it takes less energy to add an electron to a valence shell that is nearly full.
For the first ionization potential chlorine is higher than Mg. Of the choices listed A is the best BUT I don't like the reasoning of A at all.
Well, it's not surprising that Chlorine (Cl) has a higher ionization energy. I mean, who wouldn't want to hold on to their electrons when their valence shell is almost full? It's like trying to pry a sandwich out of someone's mouth who is about to take a bite, it's just not gonna happen easily. On the other hand, Magnesium (Mg) is a little more willing to part with those electrons, but only because it has more to begin with. So, to sum it up, Chlorine wins the contest of high ionization energy because it's just too greedy to let go.
Mg; it takes more energy to pull two electrons away from magnesium (Mg) than it does to take them from chlorine (Cl).
The correct answer is "Cl; it takes much more energy to pull an electron away from a valence shell that is nearly full."
To understand why chlorine (Cl) has a higher ionization energy than magnesium (Mg), we need to consider the electronic configurations of both elements.
Chlorine has the atomic number 17, meaning it has 17 protons and 17 electrons. The electronic configuration of chlorine is 1s^2 2s^2 2p^6 3s^2 3p^5. The valence shell of chlorine is the 3p orbital, which contains 5 electrons. This valence shell is close to being full, meaning it is more stable, and therefore it is difficult to remove an electron from it. As a result, chlorine has a higher ionization energy.
On the other hand, magnesium has the atomic number 12, meaning it has 12 protons and 12 electrons. The electronic configuration of magnesium is 1s^2 2s^2 2p^6 3s^2. The valence shell of magnesium is the 3s orbital, which contains 2 electrons. This valence shell is not as close to being full as that of chlorine, meaning it is less stable, and therefore it is easier to remove an electron from it. As a result, magnesium has a lower ionization energy.
In summary, chlorine has a higher ionization energy compared to magnesium because it takes much more energy to pull an electron away from a valence shell that is nearly full.