Question

An ancient club is found that contains 200 g of pure carbon and has an activity of 4.5 decays per second. Determine its age assuming that in living trees the ratio of atoms is about . Note that the half life of carbon-14 is 5700 years and the Avogadro number is

Answer 1

Explanation: initial activity = (0.693/Thalf)(N12C)(1.3*10^-12)

(0.693/5700)(200(1/12))(6.023*10^23)(1.3*10^-12)

= 1.22 *10^9 decays/year.

A = 4.5 decays/seconds