00:01
Let's say we wanted to find the beta decay.
00:05
So beta decay of radon 238, excuse me, 222.
00:17
So radon 222, we'd write the term symbol as 222 for radon.
00:24
And that symbol is rn.
00:26
It has 36 protons, excuse me, sorry, 86 protons.
00:30
So we're at 86 there.
00:34
And so the decay, meaning we're going to decay into other particles, but part one of them is going to be from the beta, right? so the beta decay of the radon is going to be, well, beta particles and electrons.
00:55
So we'll have zero for the mass, negative one for the proton number.
01:00
And so notice that negative one, 86 is going to break down, is going to equal negative one plus another number.
01:07
It has to be 87.
01:08
And that tells me immediately you can look at that and that can tell you what element to look for.
01:14
And that's francium.
01:15
And all you have to care about is adding the top number.
01:18
222 is equal to zero plus another number.
01:21
And that number is 222.
01:22
So the beta decay of radon 222 would be this equation.
01:27
And so if we wanted to do something like the alpha decay, let's say we wanted the alpha decay of uranium 238.
01:38
So the alpha decay of uranium 238, well, this is decay again.
01:42
And we have uranium, which is u for the symbol, the amount of protons it has is 92.
01:49
So we'll put that at the bottom and its mass is 238 at the top.
01:59
And that's going to decay into, well, in this case, since it's alpha decay, one of the particles is going to be a helium nucleus.
02:12
Four for the mass, two for the proton number.
02:15
And so by adding the, or figuring out the numbers that need to go, 238 is going to be equal to four plus another number.
02:23
So that's going to be 234 at the top.
02:27
234 plus four is 238.
02:29
92 is equal to two plus another number...