Question 1
A radioactive source emits 2.4-MeV neutrons at the rate of 7100 neutrons per second. The number of atoms in the source is

What is the activity of the source, in curies (Ci)? (1.00 Ci = 3.70 × 10
10 Bq)
◦ 1900 nCi
◦ 710 nCi
◦ 19 nCi
◦ 71 nCi
◦ 190 nCi
Question 2
What mass of
14C, with a half-life of 5730 y, do you need to provide a decay rate of

The mass of
14C is 14.00 u, and 1 u = 1.6605 × 10
-27 kg.
◦ 1.70 × 10
-12 kg
◦ 3.84 × 10
-20 kg
◦ 8.68 × 10
-13 kg
◦ 5.38 × 10
-19 kg