00:01
To draw the lewis structure, we need to count the total number of valence electrons.
00:05
Hydrogen has one, there are two of them.
00:07
Oxygen has six, so that's eight.
00:09
If we add in eight valence electrons, four of them will be bonding electrons, four of them will be lone pairs.
00:17
Is the molecule symmetrical? well, yes, it is.
00:21
You can divide it right in half, and you can see the symmetry right in half.
00:28
But it's not symmetrical in terms of bond polarity cancellation.
00:33
But is it symmetrical? yes, it is symmetrical.
00:36
It has a bent shape at 120 degrees.
00:40
Oxygen is more electronegative, so the top of the molecule is electronegative.
00:46
The bottom is electropositive, so the molecule is polar.
00:52
For carbon dioxide, this ends up becoming the lewis structure.
00:57
Is it symmetrical? symmetrical, yes, but not so much in the way that this is symmetrical.
01:04
So i'm going to change this from being symmetrical, yes, to symmetrical, no, because the symmetry does not allow for bond polarity cancellation.
01:12
That's why it's polar, but this one does...