# Question 611ac

Jul 18, 2017

The mass of the sample will be $= 37 g$

#### Explanation:

The half life of $U - 238$ is ${t}_{\frac{1}{2}} = {4.510}^{9} y$

This means that every $4.5 \cdot {10}^{9} y$, a sample will loose, 50% of its mass.

The time here is

$t = {4.510}^{9} y$

$t = {t}_{\frac{1}{2}}$

The time is equal to the half life. We will loose 50%# of the original mass.

So,

The mass of the sample will be $= \frac{74}{2} = 37 g$