Question

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

Answer 1

The right answer is "3 g".

Step-by-step explanation:

Given:

Initial mass substance,

`M_0=24 \ g`

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

⇒
`M=(M_0)/(2^n)`

`=(24)/(2^3)`

`=3 \ g`

Thus, the above is the correct answer.