00:01
Polar molecules result from the unequal sharing of electrons in the molecule.
00:07
So if we look at a water, h2o, oxygen is not a very good share, and they like to, and oxygen pulls the electrons more towards itself and doesn't share equally with either hydrogen.
00:28
So we end up getting an overall slight positive charge on the hydrogen sides of this triangular molecule and a slight negative charge on the oxygen side of the molecule.
00:42
I'm going to draw a second one in a different way so we can draw our hydrogen bonds.
00:51
So we'll do slight negative, positive, positive.
00:55
Okay, so hydrogen bonds form between elements or elements, regions of a molecule that are highly electronegative.
01:06
And what that means is that an electronegative sort of entity is the measure of the tendency of an atom to attract a bonding pair of electrons.
01:25
So it's the tendency of an atom, and in our example, we're using oxygen, to attract a bonding pair of electrons.
01:46
Our big electronegative atoms that we are interested in are oxygen, nitrogen, and fluorine.
01:59
And so when we look at our polar molecules, hydrogen bonds form between the electronegative atom here and here with a hydrogen.
02:17
So here and here.
02:21
So we'll use some dotted lines...