Big 7 - Chapter 6 Nuclear Reactions

Focus Assignment: Read page 343 and answer the following questions. 1 Focus Assignment: Read page 343 and answer the following questions? 1. What country receives the most electric power from fission? 2. What turns the turbines to create electricity in a fission reactor? 3. What comes out of the cooling tower of the fission reactor?

Big 7 - Chapter 6.2 – Nuclear Fission and Fusion Strong Nuclear Force Nuclear Fission Mass converted to Energy Nuclear Chain Reaction Nuclear Reactions for Energy Nuclear Fusion Fusion in the Sun and Stars

- + + + + + Strong Nuclear Force Force that holds protons in the nucleus together. Felt over the distance of three protons. + + Like Charges Repel Opposite Charges Attract + - + + Strong nuclear force causes protons to attract Less than three protons wide…

Elements higher than atomic number 83 always decay Too many protons and neutrons causes an unstable nucleus and it undergoes nuclear decay Nuclear Instability Elements higher than atomic number 83 always decay

235 U + 1n  140 Ba + 93 Kr + 3 1 n + energy 92 56 36 Nuclear Fission Process of splitting heavy nuclei into lighter nuclei (neutrons and energy produced) 2. Is bombarded by a Neutron. 1. Uranium 235 235 U + 1n  140 Ba + 93 Kr + 3 1 n + energy 92 56 36 3. It splits and produces 4. Barium 6. Releasing three neutrons 7. And a lot of energy 5. Krypton

Neutron Barium Uranium Neutron Energy Krypton Neutron

E = mc2 4. Mass converted to Energy E = energy m = mass Total mass of products is less than the reactants. Some mass is turned to energy. E = mc2 E = energy m = mass c = speed of light One gram of matter, about 20 drops of water is enough energy to power a 100 watt light bulb for 250,000,000 hours or 28,500 years. www.pitt.edu

5. Nuclear Chain Reaction A series of continuous fission reactions

Barium Uranium Krypton

5. Nuclear Reactions for Energy The heat from a nuclear chain reaction is used to create steam which turns a generator.

6. Nuclear Fusion A process by which light nuclei combine to form heavier nuclei and release energy. The mass of a nuclei is always less than its individual components… thus mass is turned to energy.

7. How the sun produces energy The sun an other stars are a series of fusion reactions to produce energy.