A radioactive element decays according to the function Q = Q0 e rt, where Q0 is
ID: 3286842 • Letter: A
Question
A radioactive element decays according to the function Q = Q0 e rt, where Q0 is the amount of the substance at time t=0, r is the continuous compound rate of decay, t is the time in years, and Q is the amount of the substance at time t. If the continuous compound rate of the element per year isr= - 0.000139, how long will it take a certain amount of this element to decay to half the original amount? (The period is the half-life of the substance.) The half-life of the element is approximately years. (Do not round until the final answer. Then round to the nearest year as needed.).Explanation / Answer
Qo/2 = Qo e^(-0.000139t)
or
-0.000139t = ln(1/2)
or
t = 4986.67 years