Question

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

• A. $12g$
• B. $24g$
• C. $36g$
• D. $48g$

Answer 1

Answer: (D)

$48g$

$N=2^{-n}{N}_0$

$N_0=2^4\times 3=48$gm (n= no. of half life = $12/3=4$)