00:01
In this case, they tell us that to ionize gold, we need 890 .1 kilojoules per mole.
00:07
So what we want to know is how many joules per molecule, i mean per atom we need.
00:14
So we're going to divide this.
00:16
We're going to take the 890 kilojoules, which is 890 .1.
00:21
Kilo means times to the 3, so times 10 to the 3 joules.
00:25
We're going to divide it by the number of atoms in one mole, which is avogato's, number times 10 to the 23.
00:32
So with that we get the energy to ionize one single atom of gold.
00:41
So this is an energy of 1 .479 times 10 to the minus 18 joules.
00:52
So the wavelength that we need, we can use planx equation.
00:57
Planx equation tells us that the energy that we need is the planks constant times the velocity of light divided by the wavelength.
01:06
So if we want to figure out the wavelength all we got to do is exchange these two.
01:10
We exchange these two and we get that the wavelength is equal to hc over the energy...
