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Chapter 16

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Chapter 16

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  1. Chapter 16 Fusion and Fission – and a new energy

  2. Nuclear Fusion: A nuclear reaction in which two nuclei combine to form a single, larger nucleus. Nuclear energy is released whenever two light nuclei are fused to create a nucleus that is lighter than iron Nuclear Fission: A nuclear reaction in which a large, single nucleus splits into two roughly equal smaller nuclei. Nuclear energy is released whenever a heavy nucleus is fissioned into two nuclei that are both heavier than iron Nuclear Energy: The energy resulting from the structure of a material’s nuclei 16.1 Fusion: Fire of the Sun

  3. The Release of Nuclear Energy is the transformation of nuclear energy into thermal or radiation • A self-sustaining fusion reaction has thermal energy, so it is called a Thermonuclear Reaction 16.1 Fusion: Fire of the Sun

  4. Nuclear Energy Curve A graph showing the energies of the different nuclei versus their mass number. The graph shows a lowest point at mass number 56 (iron), indicating that nuclear energy can be released by the fusion of nuclei lighter than iron and by the fission of nuclei heavier than iron 16.2 The Nuclear Energy Curve

  5. Big Bang • 14 billion years ago • Created space and time • Created 3 Elements • Hydrogen • Helium • Lithium (small amount of) 16.3 Origin of the Elements

  6. Fusion processes can create elements from Helium all the way up to Iron • Supernova • The explosion of a giant star • Spreads chemical elements into space • Source of elements heavier than Helium 16.3 Origin of the Elements

  7. Chain Reaction: A series of neutron-induced fission reactions that proceed from one nucleus to the next by means of the neutrons released during each fission reaction 16.5 The Chain Reaction

  8. Manhattan Project: The US project during WWII to build fission bombs • Fission bombs: A bomb that gets its energy from a fission chain reaction • Fuel can be either plutonium or a uranium isotope • Nuclear Reactor: A device to transform nuclear energy into other energy forms 16.6 The Manhattan Project

  9. Isotope Separation: Any process that increases the percentage 235U relative to 238U • Centrifuge Separation: An liquid or gas can be separated into heavier and lighter portions in a high-speed centrifuge • Highly enriched Uranium: Uranium that has been enriched to about 90% 235U which is suitable for nuclear weapons use • Kiliton: A unit of energy, the energy that would be released by 1000 tons of TNT 16.6 The Manhattan Project

  10. Hiroshima (August 6, 1945) • Japanese industrial city • 12 kilotons of nuclear energy • 200,000 dead Nagasaki (August 9, 1945) • Smaller than Hiroshima • 22 kilotons of nuclear energy • 140,000 dead 16.6 The Manhattan Project

  11. Fusion bombs: A bomb that gets its energy from the fusion of hydrogen, triggered by a fission bomb • Megatons: Unit of energy, equal to 1 million tons of TNT 16.7 Fusion Weapons

  12. Weapons of Mass Destruction: Nuclear, chemical or biological weapons • Dirty Bomb: A bomb powered with conventional explosions that does its damage primarily by the dispersal of radioactive materials 16.8 Nuclear Terrorism

  13. 4 Routes of Terrorist acquisition of Nuclear Devices (in order of plausibility) • Seizing and detonating an intact nuclear weapon • Seizing or purchasing weapons-grade uranium or plutonium • Sabotaging nuclear power plants and other nuclear facilities • Acquiring radioactive material leading to building and detonating a dirty bomb 16.8 Nuclear Terrorism