Question

The rate of decay of a radioactive element at t = 0 instant ${10}^3$ disintegrations/s. If the half- life of the elements is 1 s, then the rate of decay after 1 s will be

• A. 500 disintegrations / s
• B. 1000 disintegrations/ s
• C. 250 disintegrations/ s
• D. 2000 disintegrations/ s

Answer 1

The correct option is A 500 disintegrations / s

$\frac{A_1}{A_2}=\frac{N_1}{N_2}\therefore A_2={10}^3\times \frac{1}{2}=500$