Posted by pinky on .
radioactive disintegration is 1st order reaction. calculate the age of ancient wood piece if it shows a c14 activity of 20% compared to present day wood. if the half change time for c14 is 5600 years

chemistry 
DrBob222,
Calculate k from k = 0.693/t_{1/2} and substitute into the equation below.
ln(No/N) = kt
No = 100%
N = 20%
k from above.
Solve for t