Question

(Can you show work for these questions)

If a radioactive material decomposes with a half-life of 2 days, how much of a 16- gram sample will remain after 10 days?

A. 4.0 grams

B. 2.0 grams

C. 1.0 grams

D. 0.5 grams

If 2.5 grams of a radioactive isotope exist after 30 days in a storage vial, how much was present when it was sealed if the t1/2 = 6 days?

A. 80 grams

B. 60 grams

C. 40 grams

D. 20 grams

Answer 1

A Half life : 2 days Ending amount begning amount where n = no. of half lives. Here, initial amount Ending amount : 169 = 16 na 10/2 = 5. 2 • 106 16 25 - 0.59 Ella 26 no cef dags 230 no. o haly lives a 30% = 5. Initial amount = Ending amount x2 = 2.582 = 2.5x32 2 80g