The following numbers are the ratios of second ionization...

The following numbers are the ratios of second ionization energy to first ionization energy: Na: $9.2$ Mg: $2.0$ Al: $\quad 3.1$ Si: $\quad 2.0$ P: $\quad 1.8$ $\begin{array}{ll}\mathrm{S}: & 2.3\end{array}$ $\begin{array}{ll}\mathrm{Cl}: & 1.8\end{array}$ $\begin{array}{ll}\text { Ar: } & 1.8\end{array}$ Explain these relative numbers.

The following numbers are the ratios of second ionization energy to first ionization energy:
Na: $9.2$
Mg: $2.0$ Al: $\quad 3.1$
Si: $\quad 2.0$
P: $\quad 1.8$
$\begin{array}{ll}\mathrm{S}: & 2.3\end{array}$
$\begin{array}{ll}\mathrm{Cl}: & 1.8\end{array}$
$\begin{array}{ll}\text { Ar: } & 1.8\end{array}$
Explain these relative numbers.

Key Concepts

Ionization Energy

Ionization energy is the amount of energy required to remove an electron from an isolated gaseous atom or ion. The first ionization energy refers to removing the first electron, and the second ionization energy refers to removing an electron from the already positively charged ion. These energies offer insights into the electron distribution and how tightly electrons are held by the nucleus.

Electron Configuration

Electron configuration describes the arrangement of electrons around an atom’s nucleus. It is crucial because the electrons being removed in consecutive ionizations often come from different shells or subshells. A significant jump in ionization energy, as seen in the ratios, is typically linked to the removal of an electron from a new, more tightly bound core or inner electron shell.

Valence and Core Electrons

Atoms have electrons in both outer (valence) and inner (core) shells. Valence electrons are less tightly bound and more easily removed, resulting in lower ionization energies. The removal of a core electron, due to its higher binding energy from a stronger attraction to the nucleus and less shielding, results in a higher ionization energy. The large ratios in some elements indicate that the first electron comes from a valence shell while the second comes from a core shell.

Effective Nuclear Charge

Effective nuclear charge is the net positive charge experienced by an electron after accounting for electron-electron repulsion and shielding. As more electrons are removed, the remaining electrons experience a greater pull from the nucleus, thus drastically increasing the energy required to remove an electron from a lower shell. This concept helps explain why the second ionization energy is so much higher for certain elements.

Transcript

00:01 Okay, so we can sort of see two groups here, but the values given.

00:08 One group has values that are about the same, or they're all two or less, and another group has higher values.

00:25 So the higher values are sodium, aluminum, and sulfur, but all the rest are round two.

00:44 Okay, so these, nothing's too special about them, so they're all going to be about, two, but these very greatly, especially sodium, it's very high.

00:56 So let's look at the periodic table to try to explain this.

01:00 So we'll start with sodium.

01:03 So the first ionization energy shouldn't be too bad because you're just removing one electron from the 3s orbital.

01:11 But the second ionization energy, you're going to come down here.

01:15 It's going to have a similar electron configuration to neon, which is in the noble gas group.

01:19 So it's very stable.

01:20 So the second ionization energy should skyrocket compared to the first because you're in a completely different end level, n equals 2, which is much smaller compared to n equals 3, and you're in the noble gas configuration.

01:35 So this is going to lead to very high.

01:40 Now it's like at aluminum and sulfur.

01:42 These aren't as high as the sodium ratio was, but aluminum.

01:47 So aluminum has one electron in the p subshell.

01:53 So if it loses one, it'll become a fully fill.

01:56 S subshell.

01:58 So this is favorable...

Please give Ace some feedback