Question

The half-life period for a radioactive substance is $15$ minutes. How many grams of this radioactive substance is decayed from $50$ gram of substance after one hour?

• A. $37.5$
• B. $25$
• C. $43.75$
• D. $46.875$

Answer 1

Answer: (D)

$A_0\stackrel{15}{\to }\frac{A_0}{2}\stackrel{30}{\to }\frac{A_0}{4}\stackrel{45}{\to }\frac{A_0}{8}\stackrel{60}{\to }\frac{A_0}{16}$
$3.125g$ remain
Decayed $=46.875$