Question

The half-life of Radium-226 is 1590 years. If a sample contains 100 mg, how many mg will remain after 2000 years?

Answer 1

half-life formula: m(t) = m(sub o) e^(-rt) where r = ln2/h

m(t) = 100 * e^[-(ln2/1590)*2000]
m(t) = 100 * e^(-.87188)
m(t) = 100 * .418165
m(t) = 41.8165 mg

Answer 2

appreciate the help!