Question

A bone fragment was found from an elk which had died 40 years before. What percent of Pb-210 remains? The half-life if Pb-210 is 22 years.

Answer 1

Apply the following
The radioactive constant is
\[\lambda =\ln2/t _{1/2}\]
Where
\[t _{1/2} =22 \] years
is the half life
\[M _{t}=M _{0}*e ^{-\lambda *t}\]
t =40 years
The percentage is
\[M _{t}/M _{0} * 100 \] %