Question

The half-life of radon is 4 days. 10 gram of radon after 16 days will reduce to

• A. 2.5 gm
• B. 0.625 gm
• C. 1.625 gm
• D. 0.25 gm

Answer 1

The correct option is B

0.625 gm

Number of half – lives, $n=\frac{t}{T}=\frac{16}{4};m=m_0\frac{1}{2^{n^{\prime }}}m=10g\times \frac{10}{2^4}\Rightarrow m=0.625g$