Question

Element X decays radioactively with a half life of 9 minutes. If there are 760 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to decay to 19 grams?

Answer 1

47.9 minutes

Explanation:

Answer 2

Explanation:

760·0.5^(t/9) = 19

0.5^(t/9) = 19/760

2^(-t/9) = 0.025

-t/9 = log₂(0.025)

t = -9log₂(0.025) = 47.9 minutes