## Summary

The initial amount of a radioactive element can be determined by using the expression
1
\
, where n is the number of half-lives. The half-life of the reaction can be calculated using Equation 3.
2
The remaining concentration can be obtained by multiplying the initial concentration by 1/2 to the power corresponding to the number of half-lives.
2
The initial amount can then be calculated by subtracting the remaining concentration from the initial concentration and dividing by the initial concentration, multiplying the fraction by 100 to obtain the percent completion.
2

According to