The half-life of ²²⁸Ra is 1590 years. How long will it take for a sample of this nuclide to decay to 1.0% of its original activity?

Question

Quizplus · Accepted Answer

To find the time it takes for a sample to decay to 1.0% of its original activity, we use the formula: N(t) = N0 * (1/2)^(t/T), where N(t) is the remaining quantity, N0 is the initial quantity, t is time, and T is the half-life. Solving for t when N(t)/N0 = 0.01 and T = 1590 years gives approximately 10,600 years, which is closest to 1.1 x 10^4 years.

The Half-Life of 228Ra Is 1590 Years

The Half-Life of ²²⁸Ra Is 1590 Years