A radioactive produces 1280 decays per min at one time, and 6 hours later produces 320 per min.What?

Question

A radioactive produces 1280 decays per min at one time, and 6 hours later produces 320 per min.What?

Answer 1

if i am not wrong this is because the half life of this radioactive element is small it is in hrs.

half life is the time needed by a radioactive substance so that its mass or number of nuclei becomes half its initial value

so the number of nuclei decreases by passing time and thus the number of decays per minute decrease too

Answer 2

Are you asking what is the half life of this substance?  

Remember that the half life is the time in which half of the remaining substance decays.

So, if at the beginning we have 1280 decays per min; one half life later we will have 640 decays (since half the radioactive substance has decayed); and after two half lives have elapsed we will have 320 (or 1/2 of 640) decays per minute.  

so this problem is telling us that 6 hours corresponds to two half lives; if the problem is asking the length of one half life, the answer is 3 hours.

Answer 3

This is really a simple problem if you completed your post. It is very difficult to present a solution when the requirements of the problem are not specified.

Answer 4

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you may try this one