Question

A radioactive substance has a half life of 120 years. Presently, there are 60 grams of the substance. When were 600 grams present?

Answer 1

399

Explanation:

Using the formula `A(FInal) = A(Initial) * (1/2)^(t/h)`, you can input your information from the questions into there.
`60 = 600 * (1/2) ^ (t/120)`
`0.1 = (1/2) ^ (t/120)`
`t/120 = log_(1/2)0.1`
`t/120 = 3.21928...`
`t = 398.63137... = 399`