SOLUTION: The half-life of Radium-226 is 1590 years. If a sample contains 300 mg, how many mg will remain after 4000 years?

Question 978183: The half-life of Radium-226 is 1590 years. If a sample contains 300 mg, how many mg will remain after 4000 years?
Answer by Cromlix(4381) (Show Source): You can put this solution on YOUR website!
Hi there,
After 1 half life of 1590 years 150mg of
original 300 mg will remain radioactive.
After 2 half lives of a total of 3180 years
(2 x 1590 yrs) 75 mg of the original 300 mg
will remain radioactive.
Now 4000 yrs - 3180 yrs = 820 yrs
820/1590 = 0.52
Therefore 0.52 of 75 mg = 38.7 mg
of the original 300mg will remain radioactive.
Hope this helps:-)
RELATED QUESTIONS
the half-life of Radium-226 is 1590 years. If a sample contains 400mg, how many mg will... (answered by ikleyn)

I have this chart that talks about the half life of these and they are all different. I... (answered by CharlesG2)

I worked this problem out but would like to check with you if I'm vaguely correct: The... (answered by stanbon)

The half-life of radioactive radium (226 Ra) is approximately 1620 years. How much of a... (answered by ewatrrr)

The half-life of radium-226 is 1600 years. Suppose we have a 21-mg sample. (a) Find a... (answered by josgarithmetic)

the half life of carbon -14 is 5730 how much of 10 mg sample will remain after 4500... (answered by ankor@dixie-net.com)

The half-life of radium is approximately 1690 years. If a laboratory has 50 mg of radium, (answered by ankor@dixie-net.com)

Radium has a half-life of 1620 years. Write the decay function for a 3-mg sample. Find... (answered by ankor@dixie-net.com)

The half-life of cobalt - 60 is 5.27 years. Starting with a sample of 150 mg, after how... (answered by Theo,ikleyn)