00:01
42 .48, we're considering the alpha decay of uranium 238.
00:08
We want to figure out how much the energy changes or is released, when it emits an alpha particle, and then when it releases a neutron, a proton, a neutron, and a proton, we want to argue that the difference of this is the binding energy of an alpha particle and also then find what that is.
00:36
And then we're given a table of things we need.
00:46
So here, this decay is uranium 238, goes to thorium 234, plus helium.
01:20
So the energy that this releases is just the difference in the mass of the uranium and the mass of the products times c squared.
01:45
And so this is 4 .25 mega electron volts.
02:04
So for part b here, we have our uranium, which we pull out a neutron so that turns into uranium 237 plus a neutron.
02:35
Then we have our uranium 237, and we take out a proton.
02:45
And so this becomes protactinium, 236, i think pa is protactinium, plus a proton.
03:04
Now our protactinium 236 decays into, we take out a neutron, so it decays into protactinium 235 plus a neutron, and then our protactinium 235 decays into a proton plus thorium 234 and you'll note that we're given the masses for all of these b continued that's to keep track of things that's called the first one delta e1 and the second one delta e2 and so this is an annoying long expression but we have to do it so we have the difference in mass in uranium 238 and its products 237 uranium minus the mass of a neutron.
04:53
And we add to that the next decay and the difference in masses rather of that decay.
05:04
So the mass of the uranium 237 minus the mass of the protactinium 236 and the mass of the proton...