Question

Radioactivity of an isotope falls to $1/8$ of its original value in $48$ days. What is its half-life period (in days)?

• A. $48$
• B. $16$
• C. $12$
• D. $8$

Answer 1

The correct option is B $16$

$(\frac{1}{2}{)}^3$ of initial amount in 48 days i.e. $3$ half lives.

$3t_{1/2}=48$

$t_{1/2}=16$ days