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Learn about key discoveries in nuclear chemistry, from Rontgen's x-rays to Fermi's fission reaction. Explore fission vs. fusion reactions, effects of fission bombs, peaceful uses in power plants, and the potential of fusion energy. Understand the process of nuclear fuel processing and its relevance today. Dive into how nuclear fission differs from fusion and expertly craft a paragraph using the SUTW format for an engaging learning experience.
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Nuclear Chemistry Chapter 21B West Valley High School General Chemistry Mr. Mata
Nuclear Radiation Discoveries • Rontgen discovers x-rays (1895). • Henri Becquerel (1896) discovered that uranium salts fogged photo plates. • Marie & Pierre Curie isolated uranium atoms from pitchblende and discover elements radium and polonium (1898). • Rutherford isolates alpha & beta (1899). • Villard discovers gamma particles (1900).
Nuclear Radiation Discoveries • Rutherford discovers + nucleus (1911). • Rutherford conducts 1st transmutation (1919) • Rutherford isolates proton (1919). • Chadwick discovers neutron (1932). • Lise Meitner & Otto Hahn discover elements thorium & protactinium (1935). • Fermi achieves first fission reaction(1942). • First electricity from fission reaction (1951).
Chemical vs. Nuclear Reactions • Chemical Reaction Nuclear Reaction • Change in electrons change in nucleus (stable e- config.) (nucleons = P & N) • Temp, Press, Conc Temp, Press, Conc affect reactions. don’t affect reactions. • Energy released radioactive decay (heat & light) (alpha, beta, gamma) • Can be neutralized. Can’t be neutralized.
Nuclear Fission and Fusion • Fission:Splitting nucleus into smaller parts. • Fusion:Two nuclei combine to produce a heavier nucleus .
Nuclear Fission • Enormous amounts of energy released. • 1 kg of U-235 releases energy = 20,000 tons TNT! • Atomic bombs start uncontrolled chain reactions. • Heavy nucleus is split into smaller nuclei. • Converts mass into energy E = mc2 • 10n + 23592U [23692U] (unstable) • 23692U 9038Sr + 14354Xe + 3 10n
Nuclear Fission Bombs • First used in atomic bombs dropped on Hiroshima & Nagasaki (August 1945). • Both 23994Pu and 23592U were used. • U-235 bomb dropped on Hiroshima. • Pu-239 bomb dropped on Nagasaki. • U.S. only country to ever use nuclear bombs against enemy in war.
Effects of Fission • Atomic bomb: energy released suddenly as heat, pressure, radiation, neutrons. • Nuclear reactor: energy released slowly in the form of heat and radiation. • Neutrons released which cause other materials to become radioactive. • fission products remain “hot” for centuries.
Peaceful Uses of Fission • Nuclear power plants to generate electricity. • Fuel rods (containing U) give off neutrons. • Controlled using control rods (Zr or graphite)toabsorb neutrons. • Causes reaction to occur at steady rate. • Energy of reaction is absorbed by water (steam) which drives turbine to produce electricity.
Nuclear Fusion • Thermonuclear reaction: • Energy released from the sun • Fusion releases more energy than fission. • Fusion products not radioactive. • Takes place at very high temperatures—in excess of 40,000,000C.
Application of Fusion • Fusion reactions are used in hydrogen bombs (“H” bombs”). • More powerful than fission bombs. • H-bomb is triggered by a fission bomb. • Unsuccessful attempts have been made to harness fusion to produce controllable energy.
Processing Nuclear Fuel • Uranium ore -> uranium oxide • Uranium oxide -> uranium flouride (UF6) • UF6 (0.7% enriched U-235) • UF6 (3% enriched U-235) nuclear reactors. • UF6 (80% + U-235) nuclear weapons.
Chapter 21 SUTW Prompt • Describe how nuclear fission differs from nuclear fusion. • Complete a 8 -10 sentence paragraph using the SUTW paragraph format. Hilight using green, yellow, and pink. • Due Date: Tomorrow (start of class).