Question

A radioactive isotope decayed to 17/32 of its original mass after 60 minutes. Find the half-life of this radioisotope.

Options

• 65 minutes

• 67 minutes

• 66 minutes

• 68 minutes

Answer 1

66 minutes

Explanation:

The half-life of radioactive isotope is

`17/32 = 0.53125`

`(1/2)^"n" = 0.53125`

n log 0.5 = log 0.53125

n = 0.91254

60 minutes divided by 0.91254 equals 65.75 minutes. Therefore, n = 66 minutes.