Living organisms give a Carbon-14 decay rate of 15.3 counts/min for each gram of carbon in the sample. A sample of bristle cone pine wood has a decay rate of 3.20 counts/min per gram of carbon. Calculate the age of the wood from the radiochemical evidence. Carbon-14 has a half-life of 5770 y.

Question

Living organisms give a  Carbon-14 decay rate of 15.3 counts/min for each gram of carbon in the sample. A sample of bristle cone pine wood has a decay rate of 3.20 counts/min per gram of carbon. Calculate the age of the wood from the radiochemical evidence.  Carbon-14 has a half-life of 5770 y.

bobpursley · Answer

3.2=15.3(1/2)^-t where t is number of halflifes 3.2/15.3=.5^-t take ln of each side -1.56=-t ln(.5) t=1.56470201859/.693147181=2.235 t= 2.235*5770= check my work