A radioactive substance decays at a continuous rate of 16.1 % per day. After 17 days, what amount of the substance will be left if you started with 220 mg?

Question

A radioactive substance decays at a continuous rate of 16.1% per day. After 17days, what amount of the substance will be left if you started with 220 mg?

(a) First write the rate of decay in decimal form.

r=

(b) Now calculate the remaining amount of the substance. Round your answer to two decimal places.

Answer 1

a.

Given that, λ = 16.1/100 and A₀ = 220

r(t) = A₀e^-λt

r(t) = 220 x e^{-16.1/100 x t}

rate of decay: r(t) = 220 x e^-0.00161t

^b.

r = 220 x e^{-0.00161 x 17}

r = 14.25

Answer 2