The half-life of Radium-226 is 1590 years. If a sample contains 300 mg, how many mg will remain after 4000 years? ... ?

The half-life equation is written as:

An = Aoe^-kt

We use this equation for the solution. We do as follows:

0.5 = e^-k (1590)

k = 0.00044

An = 300oe^-0.0004 (4000)

An = 52.46 mg will remain after 4000 years

Hope this answers the question. Have a nice day.