The amount of a radioactive substance remaining after t years is given by the function , where m is the initial mass and h is the half-life in years. Cobalt-60 has a half-life of about 5.3 years. Which equation gives the mass of a 50 mg Cobalt-60 sample remaining after 10 years, and approximately how many milligrams remain?

; 13.5 mg
; 34.6 mg
; 0.2 mg
; 4.6 mg

1 answer

The equation that gives the mass of a 50 mg Cobalt-60 sample remaining after 10 years is:

m(t) = 50 * (0.5)^(10/5.3)

m(t) = 50 * 0.5^(1.8868)

m(t) = 50 * 0.341

m(t) ≈ 17.05 mg

Therefore, approximately 17.1 mg remain after 10 years.

None of the provided options are correct.