Question 1
What percentage of a radioactive substance remains after 7.00 half-lives have elapsed?
◦ 0.391%
◦ 0.78%
◦ 1.56%
◦ 3.12%
Question 2
What total energy is released when 0.75 grams of
235U undergo fission if each atom averages 3.2 × 10
-11 J of energy released?
◦ 1.45 × 10
13 J
◦ 6.01 × 10
31 J
◦ 6.15 × 10
10 J
◦ 6.15 × 10
7 J
◦ 1.45 × 10
10 J