Question 817371
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Hi,
The half-life of radioactive radium (226 Ra) is approximately 1620 years. {{{Q(t) = Q[0]e^(-kt)}}}
.5  = {{{ e^(-1620k )}}} ,  {{{ln (.5)/ -1620}}} = k,  k = .00043 
How much of a 10 gram sample will remain after 1000 years?
 {{{Q(t) = 10e^(-.00043*1000)}}}