Question

You discover some ancient charcoal at a site in western Washington. You want to know if the charcoal was the result of a natural forest fire or possible human activity. You therefore send a sample off for radiometric dating. If the sample has 5 g of C¹⁴ and 95 g of N¹⁴, then what is the most likely origin of the sample? (1/2 life of C¹⁴= 5730 years) Show your work and explain your answer.

Answer 1

Since ^14 & ^14 N are isobars no.of Radio active nuclides proportional mass ^14_6 C rightarrow ^14_7 N + ^0_-1 e + v^bar_c t_1/2 = 5730 years k = ln 2/5730 = 120.968 times 10^-6 year^-1 [^14_6 C]_t = 0 = 100 g [^14_6 C]_t = 5 g t = 1/K ln [N_0]/[N]_t = 1/(120.968 times 10^-6) times ln [100]/5 = 10755 Years. More than 10 years, it should be due to Natural forest fire.