Question

A wooden artifact from a Chinese temple has a 14C activity of 44.5 counts per minute as compared with an activity of 58.2 counts per minute for a standard of zero age. From the half-life for 14C decay, 5715 yr, determine the age of the artifact.

From the half-life for 14C decay, 5715 yr, determine the age of the artifact.

Answer 1

Answer – Given, Nt = 44.5 cpm , Ni = 58.2 cmp ,

Half life t ½ = 5715 yr ,

So decay constant ,k = 0.693 / t ½

                                  = 0.693 / 5715 yr

                                  = 0.000121 yr^-1

We know formula for the first order

ln Nt / Ni = -k * t

ln 44.5 / 58.2 = - 0.000121 yr^-1 * t

-0.2684 = -0.000121 yr^-1 * t

So, t = -0.2684 / -0.000121 yr^-1

        = 2213.4 yrs

So the age of the artifact is 2213.4 yrs