posted by shylo on .
please help me with this chemistry problem.
A radium-226 sample initially contains 0.112 mol. How much radium-226 is left in the sample after 6400 years? The half-life of radium-226 is 1600 years.
6400 years is 4 half-lives. The amount remaining is
0.112 mol * (1/2)^4
= 0.112/16 = 0.007 mol