Question

The radioactive isotope 14C has a half-life of approximately 5715 years. A piece of ancient charcoal contains only 81% as much of the radioactive carbon as a piece of modern charcoal. How long ago was the tree burned to make the ancient charcoal

Answer 1

Answer:

1758 years

Step-by-step explanation:

0.693/t1/2 = 2.303/t log No/N

t1/2 = half life of the C-14

t= time taken

No= amount of radioactive material originally present

N= amount of isotope after time t.

But N= 0.81 No

0.693/5715= 2.303/t log No/0.81No

0.00012 = 0.211/t

t =0.211 /0.00012

t= 1758 years