Question

How much of a 24-gram sample of Radium-226 will remain unchanged at the end of three half-life periods?

Answer 1

Answer:

The right answer is "3 g".

Explanation:

Given:

Initial mass substance,

$M_0=24 \ g$

By using the relation between half lives and amount of substances will be:

⇒ $M=\frac{M_0}{2^n}$

        $=\frac{24}{2^3}$

        $=3 \ g$

Thus, the above is the correct answer.