Question

radium has a half life of 1,620 years. in how many years will 10g of radium decay and reduce into 1g?

Answer 1

\[k=\frac{ \ln2 }{t _{1/2} }\]

find the decay constant, k.

then use the exponential decay/growth equation:

\[A=A _{0}e ^{-kt}\]

A = amount of material after time elapsed. so for you question, 1 g.
Ao= initial amount of material, 10 g.
e= euler's number
k= decay constant
t= time elapsed, i.e. what you're solving for