A bone was found to be approximately 24000 years old. The current amount of carbon-14 in the bone was 5.000 atoms. How many atoms must the bone have had originaly, assuming that the half-life of carbon-14 is approximately 6000 years?
About 80 atoms.
The equation for 1st order decay is:
Taking natural logs of both sides
We need to find
Probably 80 thousand as opposed to 80.
Michael's answer is mathematically correct but (as I commented there), 5.000 may mean five thousand as rendered in Europe. Assuming the usual measurement techniques for C-14 we probably could not resolve five atoms in the measurenent but could resolve five thousand.