Question

Technetium-99 is an ideal radioisotope for scanning organs because it has a half-life of 6.0 h and is a pure gamma emitter. suppose that 80.0 milligrams were of tc-99 were prepared at 6:00 am, how many milligrams of tc-99 would remain at 6:00 pm the same day? make sure to include units in your answer.

Answer 1

Answer: 20 mg Te-99 remains after 12 hours.

Explanation:  N(t) = N(0)*(1/2)^(t/t1/2)

                        N(t) = (80 mg)*(0.5)^(12/6)

N(t) = 20 mg remains after 12 hours