question_answer 23)

The half life for radioactive decay of 14C is 5730 y. An archaelogical artefact contained wood had only 80% of the 14C found in a living tree. Estimate the age of the sample. 

Answer:

t1/2 = 5730 y Let the amount of 14C present in the wood originally (i.e., the same which the living tree has) = a. Then, the amount of 14C present now in the old wood (a ? x) =   Time `t' in which 14C changed from a to 0.8a. (i.e., the age of the sample) will be given by   or = 19042 [log 10 ? log 8] = 19042 [1 ? 0.9030] = 19042 x 0.097 = 1847 years.