Question

A radioactive isotope having a half-life of 3 days was received after 12 days. It was found that there were 3 gm of the isotope in the container. The initial weight of the isotope when packed was:

• A. 12 gm
• B. 24 gm
• C. 36 gm
• D. 48 gm

Answer 1

The correct option is D 48 gm

$n=\frac{12}{3}=4$
$\therefore N_0=N\times 2^n$
$=3\times 2^4=48gm$