Radium-223 has a half-life of 11.4 days.Approximately how long would it take for the activity of a sample of Radium-223 to decrease to 1.00% of its initial value?

Answer 1

(100)*1/2^n=1

Solve for n

1/2^n=1/100

2^n=100

n=ln(100)/ln(2)

n* the number of days (11.4) =should give you the length of time it takes for Radium-223 to decrease to 1.00% of its initial value.

Answer 2

75.7 days