00:03
So this question is asking about atomic number and atomic mass and what information they provide.
00:09
And it's a four -part question.
00:11
So i've done, as an example, i've used lithium here.
00:14
So lithium has an atomic number.
00:17
So this one is the atomic number of three.
00:22
And the atomic weight is seven.
00:26
So the information that that gives us, of course, is the atomic number is the number of protons.
00:31
The atomic weight is the number of protons and neutrons combined.
00:35
So if we wanted to find the number of protons in the atom, well, that is by definition, the atomic number.
00:47
We don't need the atomic weight.
00:50
We only need the atomic number here because that by definition is the number of protons.
00:54
Part b says the number of neutrons...