Posted by Mimi on Sunday, April 18, 2010 at 11:37am.
one eighth is three half-lives.
Now the hard way:
amount left=original amount(1/2)^t/thalflife
1/8=(1/2)^t/th
t/th=3
or even harder:
amountleft=original*e^-.693t/th
1/8=e^-.693 t/th
ln of each side
ln (1/8)=-.693 t/th
-2.0793=-.693 t/th
t/th= 3
the question ask how old is the sample in yr. so that mean t/th is 3 yrs.
Related Questions
nuclear physics - Calculate the age of a plant sample that shows about one-...
college Geol 101 - Suppose you have a sample of clamshell at a Paleoindian site ...
nuclear - Calculate the age of a plant sample that shows about one-eighth of the...
geology - suppose you have a sample of clamshell at a paleoindian site and you ...
college geology help please - I was the same person from yesterday. I need help ...
ChemB - The activity of carbon 14 in living tissue is 15.3 disintegrations per ...
Chemistry - The cloth shroud from around a mummy is found to have a carbon-14 ...
physics - A wooden artifact is found in an ancient tomb. Its carbon-14 activity ...
physics - How do I do this ? Calculate the age of a plant sample that shows ...
chemistry - A wooden object from a prehistoric site has a carbon-14 activity of ...
For Further Reading
