Help!:
Radiometric dating is the workhorse of absolute dating. If you had a sample with a radioactive component with a half-life of 5000 years and an initial concentration of one part per million, how much would be present after 5000 years? After 10,000 years? After 50,000 years? When does the radioactive material completely disappear?

Question

Help!:
Radiometric dating is the workhorse of absolute dating.  If you had a sample with a radioactive component with a half-life of 5000 years and an initial concentration of one part per million, how much would be present after 5000 years?  After 10,000 years?  After 50,000 years?  When does the radioactive material completely disappear?

anonymous · Answer

do you know what "half life" means? it is the time it takes to decrease by one half of the original amount

anonymous · Answer

so after one half life, there is half the original amount because... that is the meaning of "half life"

frank0520 · Answer

yes, I am just confuse in the initial concentration of one part per million

anonymous · Answer

what is half of one part per million?

anonymous · Answer

silly answer (but true) is half a part per million

frank0520 · Answer

is it 5000*10^6

anonymous · Answer

whoa you are thinking too hard 
you got 1 part in a million, half of that  is half a part per million, which is one part in __ million 
fill in the blank

frank0520 · Answer

.5 million ?

anonymous · Answer

no

anonymous · Answer

one part in half a million is the same as TWO parts per million