(Solved): Strontium- 90 has a half-life of 28 days. (a) A sample has initial mass of 50 mg . Find a formula f ...

Strontium- 90 has a half-life of 28 days. (a) A sample has initial mass of 50 mg . Find a formula for the mass remaining after

days,

.

(b) Find the mass (in mg ) remaining after 20 days. (Round your answer to one decimal place.) mg (c) How long does it take (in days) the sample to decay to a mass of 2 mg ? (Round your answer to the nearest day.) days