The cadmium isotope 109Cd has a half-life of 462 days. A sample begins with 1.0 * 1012 109Cd atoms. How many are left after (a) 50 days, (b) 500 days, and (c) 5000 days?
1 - R ==10^12 x 1/2^(50/462)
R==10^12 x 0.92772870876
R ==927,728,708,762 - atoms remain after 50 days.
2 - R ==10^12 x 1/2^(500/462)
R ==10^12 x 0.47229131720
R ==472,291,317,203 - atoms remain after 500 days.
3 - R ==10^12 x 1/2^(5000/462)
R ==10^12 x 5.5220408368 x 10^-4
R ==552,204,084 - atoms remain after 5000 days.
