Question

A hospital uses cobalt-60 in its radiotherapy treatments for cancer patients. Cobalt-60 has a half-life of 7

years. The hospital has 228 g of cobalt-60. Calculate the amount of colbalt-60 remaining after 18 months.
Round to two decimal places.

Answer 1

We have 197 g of Co-60 after 18 months.

Explanation:

We can use the decay equation.

`M_(f)=M_(i)e^(-\lambda t)`

Where:

• M(f) and M(i) are the final and initial mass respectively
• λ is the decay constant (ln(2)/t(1/2))
• t(1/2) is the half-life of Co
• t is the time at the final amount of m

`M_(f)=228e^{-(ln(2))/(7) 1.5}`

`M_(f)=197\: g`

Therefore, we have 197 g of Co-60 after 18 months.

I hope it helps you!