1. Nuclear Reactions PS 2.6 – 2.7

2. Fission vs. Fusion Nuclear Reactions occur within a heavy atom (not between 2 or more atoms) ex. uranium 1. Fission: when a nucleus splits into 2 or more parts – releasing lots of energy! How does it work? A. A neutron penetrates the nucleus of an atom B. As nucleus splits, it becomes a smaller nuclei (which also releases more neutrons)

3. 1. Chain reaction: occurs if one or more ejected neutrons strikes another nucleus & more split 2. Chain reactions occur in power plants & bombs 3. The mass of the products is less than what you start with (reactants). Why? E=mc 2 Where did the mass go?

4. 2. Fusion: occurs when light nuclei (hydrogen) combine to make larger nuclei (helium) A. Naturally occurs on the sun (in stars) B. Energy is released as nuclei combine. C. Requires huge amounts of energy, but it releases more energy than is needed to start it. D. Fusion for human use is still in development!

5. 3. Nuclear Technology in Use A.Medicine 1. radiation to destroy cancer (fast- growing cells) 2. radiation can allow us to view organ systems by tracking where it goes. 3. difficult to not damage healthy cells 4. waste products are dangerous

6. B. Weapons 1.Deterrent to war (enough to destroy all life) 2.Easily smuggled 3.Huge destruction

7. 4. Contaminate environment 5. Waste is dangerous for thousands of years

8. C. Power: used to produce electricity (Catawba on Lake Wylie) 1.A controlled fission reaction is used to heat water into steam (spins magnet) that creates electron flow (electricity)

9. 2. Benefits: a. high energy from little fuel b. no CO 2 pollution c. abundant fuel 3. Drawbacks: a. thermal pollution to water systems b. waste is extremely dangerous c. leaks or explosions are devastating

10. Chernobyl