A sample of radioactive material A, that has an activity of 10m Ci(l Ci=3.7 1010decays/s), has twice the number of nuclei as another sample of a different radioactive maternal B which has an activity of 20mCi. The correct choice for hall-lives of A and B an would then be respectively:
a. |
20 days and 5 days |
b. |
20 days and 10 days |
c. |
5 days and 10 days |
d. |
10days and 40days |
A sample of radioactive material A, that has an activity of 10m Ci(l Ci=3.7 1010decays/s), has twice the number of nuclei as another sample of a different radioactive maternal B which has an activity of 20mCi. The correct choice for hall-lives of A and B an would then be respectively:
a. |
20 days and 5 days |
b. |
20 days and 10 days |
c. |
5 days and 10 days |
d. |
10days and 40days |
Activity A= N
For A 10=(2N0) A
For B 20=N0 B
B=4 A (T1/2)A=4(T1/2)B