Question

Radioactive decay question: the half-life or radioactive radium is 1620 years. What percent of a present amount of radioactive radium will remain after 100 years

Answer 1

\[A=A _{0}(\frac{ 1 }{ 2 })^{\frac{ t }{ t _{1/2} }}\]

A= amount lost
Ao=initial amount
t1/2= half life
t= time elapsed

Answer 2

sorry A= amount after time elapsed, not lost