00:01
In this problem, we're talking about the mass defect of hydrogen nuclei.
00:06
And this is important because this has a direct application.
00:10
This could be seen as the reaction that occurs in the sun.
00:13
This is hydrogen nuclei reacting.
00:16
So the way that we're going to figure this out is that we're going to use the famous equation, e equals mc squared.
00:23
The only difference is, in this case, we're going to have e equals a delta mc squared.
00:28
So what does that mean? we have to find the mass defect, the change in mass in this overall reaction that we're given.
00:37
And in this reaction, just to review it, we're given two hydrogen nuclei that's going to form two hydrogen nuclei plus a positron.
00:49
So how do we find the mass defect to plug into our equation? well, this is actually a lot of calculation to do.
00:55
We're going to get the delta m equals the mass of our two hydrogen nuclei plus our positron minus two times the mass of our one hydrogen nuclei.
01:09
So you can, another way to think about this is that this is just the mass of the products minus the mass of the reactants.
01:16
Okay, so now let's start this calculation.
01:19
Delta m is going to be equal to 2 .01410 minus 2 times 1 .0 .0 .0.
01:26
0 .0782 minus 5 .485 .08 times 10 to the negative fourth.
01:35
Okay.
01:37
So now we're going to simplify this.
01:38
Delta m equals negative 4 .4 -284 times 10 to the negative 4th.
01:44
This is an amus per nucleus.
01:47
And then we can convert it into kilograms per nucleus...