00:01
To determine whether or not the molecule or polyatomic ion is polar, it's helpful to draw the lewis structure.
00:08
So for the first one, we have ch2 -cl.
00:12
Carbon has four valence electrons, ch3, cl.
00:17
Hydrogen has one.
00:18
There are three of them, and chlorine has seven.
00:21
So we have a total of 14 valence electrons.
00:24
If we put carbon in the middle and we bond three hydrogens to it, and then one chlorine, and we give chlorine an octet, we would have used up 2, 4, 6, 8, 10, 12, 14, and this would be the lewis structure.
00:42
Because the lewis structure is tetrahedral and not all bonds are the same, then this will be polar, where the more electronegative chlorine will be partially negative, and the bottom of the molecule, where the hydrogens are, will be partially positive.
00:59
So the atom closest to the negative side is chlorine, the most of the molecule.
01:02
Electronegative one.
01:05
Next we have ch2o.
01:08
Carbon has four valence electrons...