Question

The half-life of Radium-223 is 11.43 years. What is the annual decay rate? Express the result to four decimal places.

Express the annual decay rate as a percentage to two decimal places.
%

Answer 1

Below

Explanation:

e^(-kt) = 1/2 when t = 11.43

so k = .060642797

e^ (- .060642797 * 1) = .9411 <==== is left after one year

which means the decay in one year is

1 - .9411 = .05884 = 5.88% per year