Question

Tungsten, W-181 is a radioactive isotope with a half life of 121 days. If a medical lab purchase 24 kg of W-181 how much will be left after 1 year?

Answer 1

3 kg because one year is approximately 3 half-lives of W-181. The amount remaining would be 1/23 or 1/8. That is 3 kg of W-181.

Answer 2

2.97 kg.

Explanation:

We have been given that Tungsten, W-181 is a radioactive isotope with a half life of 121 days.

We will use half-life formula to solve our given problem.

`A=a\cdot ((1)/(2))^{(t)/(h)}`, where,

A = Final amount.

a = Initial amount,

t = Time,

h = Half life.

Upon substituting our given values in above formula we will get,

`A=24\cdot ((1)/(2))^{(365)/(121)}`

`A=24\cdot 0.1235760503818562`

`A=2.9658252091\approx 2.97`

Therefore, 2.97 kg of W-181 will be left after 1 year.