In the formula A Iekt A is the amount of radioactive materi

In the formula A = Ie^kt A is the amount of radioactive material remaining from an initial amount l at a given t met and k s a negative constant determined by the nature of the material. A certain radioactive isotope has a half-life of approximately 1850 years. How many years would be required for a given amount of this isotope to decay to 20% of that amount? 1480 yr 4296 yr 596 yr 4276 yr

Solution

0.20A = A (1/2)^[t/1850]
0.20 = (1/2)^[t/1850}

log(0.2)=[t/1850]*log0.5

t/1850= log0.2/log0.5 = 2.321928
t = 4295.6 yrs. (option B )