The half-life of strontium-90 is 28 years. How long will it take a 80-mg sample to decay to a mass of 32 mg? (Round your answer to the nearest whole number.)

Answer 1

32 = 80(0.5)^t/28

0.4 = 0.5^t/28

ln 0.4 = (t/28)(ln 0,5)

Can you calculate t and answer?