Valence

So I'm going to give Jem some keywords and he's going to kind of explain the process.

So the way we get color in corundum is through trace elements and through intervalence.

intervalence charge transfer.

But we're going to get into that in just a second.

I

Yes.

Okay.

So like I just mentioned, we have intervalence charge transfer.

Atoms are most stable when they have a full outer shell of electrons.

That's, we often call that a valence shell.

Okay? And so if it has, like, you know, if the valence shell can hold eight electrons, but it only has seven, the atom only has seven, it's really easy for that atom then to pick up an electron.

And all of a sudden, the valence shell goes from seven to eight, and bam, it's stable right there.

And so that is like the chlorine atom in the bottom of that third image.

It needs one more electron to make a full shell.

Sodium, it's lost an electron, so overall it has a positive charge.

Chlorine has gained an electron, overall has a negative charge.