Question

The half-life of random is 3.8 days. Three fourth of a radon sample decay in:

• A. 5.02 days
• B. 15.2 days
• C. 7.6 days
• D. 11.4 days

Answer 1

Answer: (C)

Given: half-life of radon is 3.8 days remained radon is $1-\frac{3}{4}=\frac{1}{4}$ $\frac{1}{4}={\left(\frac{1}{2}\right)}^2={\left(\frac{1}{2}\right)}^n,$ so, $n=2$ = half life $\times$ days = 2 $\times$ 3.8 = 7.6 days