12th grade
posted by Moe .
The radioactive isotope of Carcon (^14C)has a half life of 5730.
What is the decay constant of ^14C?
If we start with a sample of 1000 carcon nuclei, how many will be left in 22920 years time?

12th grade as the school subject, doesn't help much. Please say Math, Science, whatever it may be to get help from the correct volunteer teacher.
Sra