<PRE><B>Question 288554</B>
The half-life of radium is 1690 years. If 60 grams are present now, how much will be present in 440 years?
-----------------
A(t) = Ao*(1/2)^(t/1690)
---
A(440) = 60*(1/2)^(440/1690)
---
A(440) = 60*0.8349
---
A(440) = 50.093 grams
==========================
Cheers,
Stan H.</PRE>