Question

The half-life of ¹⁴C is 5730 years. The activity of carbon in living being is 12.5 counts per minute per gram of carbon. Calculate the activity of carbon from the remains of an organism that died 50,000 years ago.

Answer 1

half - life (T) = 5730 years

Tage = 50000 years

x= 12.5 dpm (living specimen)

y= ? (old specimen)

formula :

Tage = T log_e (x/y)/0.693

         = 2.303 T log (x/y) / 0.693

50000    = 2.303 x 5730 * log(12.5/y) /0.693

2.6257 = log(12.5/y)

422.37 = 12.5/y

y= 0.0295

y = 0.0295

the activity of carbon from the remains of an organism that died 50,000 years ago is 0.0295 count per min per gram