1. Week 7 1. Radioactive isotopes find practical use in all of the following applications except
Biomedical tracers
Smoke detectors
Household cleaning agents
Cancer treatment
2. The dream of ancient alchemists was to transform lead into gold. Today, it is theoretically possible to make the dream come true. Which one of the following would allow lead to be transformed into gold?
Chemical reaction
Physical change
Combustion
Nuclear fission

2. 3. What type of nuclear reaction results in a single nucleus undergoing a decrease in atomic number, no change in mass number, and the release of high light energy?
Alpha decay C. Gamma radiation
Beta decay D. Nuclear fusion
4.According to the graph, what is the approximate half-life of throium-234?
10 days C. 25 days
50 days D. 100 days

3. 5. A radioactive substance has a half-life of 40 years
5. A radioactive substance has a half-life of 40 years. What fraction of the sample will remain at the end of 160 years?
½ C. 1/8
¼ D. 1/16
6. Nuclear Reactions produce a tremendous amounts of energy. Where does the energy originate?
The conversion of mass into energy
The valence electrons during chemical bonding
The conversion of thermal energy into nuclear energy
The extreme temperatures produced during nuclear reactions

4. 8. Describe the reaction illustrated by:
7. Which subatomic particle is used as a projectile to start a fission reaction?
Proton
Neutron
Electron
Alpha particle
8. Describe the reaction illustrated by:
1H + 2H  3He
Fission
Alpha decay
Gamma decay
Fusion

5. 9. A group of identical atoms would be classified as
A solution.
A compound.
An element.
A mixture
10. Carbon dioxide, CO2, is an example of a(n)
Solution
Compound
Element
Mixture