00:01
All right, in this question, we are given a number of elements and we are asked to predict empirical formulas.
00:07
So the trick to figuring out a question like this is to predict the charges on the ions that would be involved in the ionic bond.
00:18
So lithium, lithium is a group 1a.
00:22
It's got one valence electron.
00:24
It's easier for lithium to lose that electron.
00:27
Remember, all alkali and alkaline earth.
00:30
Metals like to lose their electrons to form ions.
00:34
Then everything right of carbon likes to gain electrons.
00:40
So nitrogen has five electrons.
00:43
It needs three more to form the octet.
00:45
So we would expect nitrogen to have a three minus charge.
00:49
Lithium has one electron.
00:51
It wants to lose it.
00:52
So we would expect it to have a positive charge.
00:56
Now, in order for these charges to cancel, we are going to need three lithiums for one nitrogen.
01:02
There's 3 times 1 minus 3, so 3 minus 3 is 0.
01:06
It counts us up.
01:07
Okay.
01:08
Next up we have gallium and oxygen.
01:11
Gallium is over here.
01:18
Gallium is in group 3a, and it's got three electrons...
