Question

At time t = 0 you have 100 grams of radioactive Chromium-48. Ten hours later you have 74 grams left. What is the half life of Chromium-48?

Answer 1

To calculate what is asked we use the formula for radioactive decay. It is expressed as follows:

An = Ao (e^(-kt))

We calculate as follows:

An = Ao (e^(-kt))
74 = 100 (e^(-k(10)))
k = 0.0301

1/2 = (e^(-0.0301t))
t = 23 hours

Hope this answers the question.