A radioactive isotope is being produced at a constant rate dN/dt = R in an experiment. The isotope has a half-life t1/2. Show that after a time t >> t1/2, the number of active nuclei will become constant. Find the value of this constant.

Given, rate of radioactive isotope production= R

Rate of decay= λN ( According to law of Radioacivity)


As activity decreases exponentially and after a time t >> t1/2, the number of active nuclei will become constant and rate of decay will also become constant.


So, (dN/dt) produce=(dN/dt) decay=R


R= λN


N= =


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