A sample contains 20 kg of radioactive material. The decay constant of the material is 0.179 per second. If the amount of time that has passed is 300 seconds, how much of the original material is still radioactive? Show all work

Explanation:

Given

N0 = 20kg (original substance)

decay constant λ = 0.179/sec

time t = 300s

We are to find N(t)

Using the formula;

n(t) = N0e^-λt

Substitute the given values

N(t) = 20e^-(0.179)(300)

N(t) = 20e^(-53.7)

N(t) = 20(4.7885)

N(t) =143.055

To know how much of the original material that is active, we will find N(t)/N0 = 143.055/20 = 7.152

About 7 times the original material is still radioactive

what is the question?