Question

The half-life of $215 ⥂ At$ is$100\mu s$. The time taken for the radioactivity of a sample of $215 ⥂ At$ to decay to 1/16^th of its initial value is.

• A. $400\mu s$
• B. $6.3\mu s$
• C. $40\mu s$
• D. $300\mu s$

Answer 1

Answer: (A)

$400\mu s$

Answer 2

The radioactivity of a sample decays to $\frac{1}{16}th$of its initial value in four half lives.