00:01
In this video, we are going to write formulas and names for ionic compounds form from these combinations of cations and anions.
00:07
And as a basic principle, if you have something that's positively charged with some charge x plus and something that's negatively charged with the charge of y minus, then you take the cat ion and you'll put the subscript y and then the anion with the subscript x.
00:25
And that way you'll have the same overall positive and negative charge.
00:28
So you're basically crossing the charges.
00:31
And if x is equal to y, then just make both of them one.
00:35
And then you'll get a b because the ratio, if this is a three, this is also a three.
00:40
You don't need to write both the three.
00:43
So that's our principle.
00:45
So if you have n .a.
00:46
Plus one and s2 minus, then it's going to be n .a .2 .s.
00:52
And we never write the one.
00:53
So n .a2s.
00:56
I'm going to write the names after.
00:57
So it's the same thing, k2, s -o -3 with a 1.
01:03
F -e, in this case, 1, and then the nitrate, n -o -3, is going to be to the third.
01:12
And if we have a polyatomic ion, we always put it in parentheses when there's more than 1.
01:16
All right, cu2 plus and s2 minus.
01:18
That's just c -u -s because they have the same charge.
01:22
Okay, so we have a plus 1 and a minus 2.
01:24
So we need this first one to be to the 2.
01:29
And the second one just one.
01:31
Again, in parentheses.
01:33
All right.
01:33
Plus and then a minus three, so k3 and one, p -o -4.
01:40
Plus two and a minus two, so this is a one -to -one ratio.
01:46
Plus three minus three, also a one -to -one ratio.
01:52
Plus one -minus one, so one -to -one.
01:57
We already did this one.
02:00
We already did that one.
02:01
Okay, at two into three, so ca3, p -o -4 -2.
02:09
2 -02, so f -e and then s -o -4.
02:13
1 and a 2, so n -a -2 -s -o -4.
02:18
All right, now for the names.
02:21
So by convention, you're going to name the name of the cat -ounds, in this case, sodium.
02:27
And then the name of the anion ending in i -d -e if it's a single atom.
02:36
So like sulfur...