Answer to Question #135397 in Physics for vijay malik

Question

calculate the radioactive constant for an element whose half life is 20 years

Answer 1

The radioactive constant

$$\lambda=\frac{\ln 2}{t_{1/2}}\\ =\frac{\ln 2}{20\times 365\times 24\times 3600\:\rm s}=1.098\times 10^{-9}\:\rm s^{-1}$$