00:01
Okay, so in this question, they tell us that the half -life is one hour, the time pass is three hours, and the activity initial is 1 ,000 atoms per second.
00:10
So the equation that we need to solve for this question is ln, activity final over activity initial, is equal to the negative decay constant times it by the time pass, right? so looking at choices, it looks like they want the answer in a second.
00:27
So we must convert the half -life and the time pass to second.
00:31
Right, we know that one hour has 3 ,600 seconds.
00:35
If we multiply it out, we get 3 ,600 seconds.
00:39
And three hours times it by 3 ,600 seconds, we get 10 ,800 seconds.
00:45
Right.
00:46
So now let's solve for activity final, because that's what they want from this equation.
00:51
So we know that we put e to the ln activity final over activity initial...