Question

an animal carcass had 24 grams of carbon 14 when it was alive and 3 grams when its fossilized remains were discovered how old is the fossil?

Answer 1

The carbon 14 left from this animal is 3 grams of 24 grams which is: 3g/24g= 1/8 times of its original mass. Then, the age of the animal fossil would be:

final weight= initial weight * (1/2) ^ time/half-live
1/8 initial weight = initial weight  * (1/2) ^ time/half-live
log2 1/8= log2 (1/2) ^ time/half-live
-3= -time/half-live
time= -3 * -(half-live)
time= 3 half-live

If the half-live is 5730 years, the age would be: 3* 5730= 17.190 years.