pre algebra
posted by Anonymous .
The halflife of 234U, uranium234, is 2.52 105 yr. If 98.6% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

.986=e^(.693t/2.52E5)
take the ln of both sides..
> 0.0140989244=.693t/2.52E5
solve for t
t== 0.693147181*2.52E5/0.0140989244
I get a little over 12 million yars