00:06
So we're going to try to figure out what is the mass of 500 grams of iron, 500 atoms, excuse me, iron.
00:15
I have 500 atoms of iron.
00:21
Just kind of break down the problem.
00:23
We're going to have to go from atoms to moles, then to grams.
00:36
So one of our first steps is we know that the relationship between atoms and moles that there are 6 .0.
00:44
2, 2 times 10 to the 23 particles, molecules, in this case atoms per every one mole.
00:57
And so we're going to use that conversion factor to be able to go from atoms to moles.
01:01
And then in order to go from moles to grams, i'm going to need the molar mass of what iron is.
01:07
And we'll look that up on our periodic table.
01:10
And if you look and you find iron on your periodic table, you see, for example, iron iron as an average atomic mass, its molar mass is 55 .85.
01:32
And iron also has 26 protons.
01:43
So to set this up, we're going to set it up as a simple stoichiometry type problem.
01:49
And so in this case we know there are 55 .85.
01:52
You can think of grams of iron for every one mole of iron.
01:58
So these are the conversions, once again, that we're going to use.
02:02
And so what i'm going to do is i'm going to start out with the amount i have.
02:06
So i have 500 atoms of iron.
02:17
And i'm going to go ahead and i want to convert those atoms once again to moles.
02:21
So i'm going to use this conversion factor...