Question

A radioactive substance decays exponentially. A scientist begins with 130 milligrams of a radioactive substance. After 24 hours, 65 mg of the substance remains. How many milligrams will remain after 45 hours?

Answer 1

N(t)=N∗.5t/h where n(t) is amount of substance left, N = initial amount, t = current time, and h = half-life time.h = 24 hours t= 45 hours, N = 130mg
therefore, N(t)=130∗.545/24=35.44mg