0:00
Okay.
00:01
So for this question for part a they are asking us what fraction of the sodium 24 nikolai will remain un decayed after 12 hours if the half life is 15 hours.
00:11
So we have to have five is equal to 15 hours.
00:15
We have time past is equal to 12 hours.
00:21
And we need to equations in order to solve this question.
00:25
So the first one is ellen n.
00:29
T.
00:29
So this is nuclear.
00:31
After a certain amount of time over and not which is the initial amount of the nuclei present is it goes to negative k.
00:39
Times t.
00:39
K.
00:40
Is decay constant.
00:41
T.
00:41
Is the time pass which we have right here.
00:44
And the next equation is k.
00:47
Which is to take a constant is equal 2.693 over half life.
00:55
Right? so the first thing that we can do is we can plug k into this equation over here.
01:00
So we get ln empty over and not 02 .693 times by t over.
01:13
If you half life.
01:14
Okay.
01:16
Mhm.
01:17
Now let's start plugging in some of the numbers.
01:21
Mhm.
01:21
Okay so we have helen and t.
01:26
Over and not 02.693 times by t.
01:32
Which is 12 hours over the half life.
01:36
Which is 15 hours.
01:40
Mhm...