Question

Suppose a radioactive nucleus has a half-life of 2 min. and suppose the counting rate at t = 0 is 3000 counts/s. 

a. What is the counting rate after 2 min? 

b. After 6 min? 

c. After 10 min? 

d. After 20 min? 

e. What is the mean life of this nucleus? 

f. Suppose that the Geiger counter detects 10% of all the radioactive decays. 

What is the total number of radioactive nuclei at time t=0? 

g. What is the total number at t 2 min? 

h. How many nuclei decay in the first 2 minutes? 

i. What is the initial decay rate? 

j. Why is the answer in h. not equal to the answer in i. times 120 sec?

Answer 1