nuclear chemistry

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Nuclear Chemistry. Nuclear Symbols. Mass number (p + + n o ). Element symbol. Atomic number (number of p + ). Types of Radioactive Decay. 4. 2+. alpha production ( a ): helium nucleus beta production ( b ):. He. 2. 0. e. 1. -. Alpha Radiation. - PowerPoint PPT Presentation

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  • Nuclear SymbolsElement symbolMass number (p+ + no) Atomic number (number of p+)

  • Types of Radioactive Decayalpha production (a): helium nucleus beta production (b): 24He-10e2+

  • Alpha RadiationLimited to VERY large nucleii.

  • Beta RadiationConverts a neutron into a proton.

  • Types of Radioactive Decaygamma ray production (g): positron production : electron capture: (inner-orbital electron is captured by the nucleus)10e

  • Type of radiation emitted & symbolNature of the radiation Nuclear SymbolPenetrating power, and what will block it Effect of release of particles from the nucleusAlpha a helium nucleus of 2 protons and 2 neutrons, mass = 4, charge = +2Low penetration stopped by a few cm of air or thin sheet of paperReduces the atomic mass number by 4 Reduces the atomic number by 2 Beta high kinetic energy electrons, mass = 1/1850 of alpha, charge = -1Moderate penetration, most stopped by a few mm of metals like aluminumIs the result of neutron decay and will increase the atomic number by 1 but will not change the mass numberGamma very high frequency electromagnetic radiation, mass = 0, charge = 0Very highly penetrating, most stopped by a thick layer of steel or concrete, but even a few cm of dense lead doesn't stop all of it!Is electromagnetic radiation released from an excited nucleus. The atomic number and mass number do not change.

  • Deflection of Decay ParticlesOpposite charges_________ each other.Like charges_________ each other.attractrepel

  • NuclearStabilityDecay will occur in such a way as to return a nucleus to the band (line) of stability.

  • Half-life Concept

  • Sample Half-Lives

  • A Decay SeriesA radioactive nucleus reaches a stable state by a series of steps

  • Nuclear Fission and FusionFusion: Combining two light nuclei to form a heavier, more stable nucleus. Fission: Splitting a heavy nucleus into two nuclei with smaller mass numbers.

  • Energy and MassNuclear changes occur with small but measurable losses of mass. The lost mass is called the mass defect, and is converted to energy according to Einsteins equation: DE = Dmc2 Dm = mass defect DE = change in energy c = speed of lightBecause c2 is so large, even small amounts of mass are converted to enormous amount of energy.

  • Fission

  • A Fission Reactor

  • Fusion

  • Chemical Fission Fusion Sample ReactionC + O2 -> CO2n + U-235 -> Ba-143 + Kr-91 + 2 nH-2 + H-3 -> He-4 + nTypical Inputs (to Power Plant) (Fuel)Bituminous CoalUO2 (3% U-235 + 97% U-238)Deuterium & LithiumTypical Reaction Temperature (K)700 K1000 K108 KEnergy Released per kg of Fuel (J/kg)3.3 x 107 J/kg2.1 x 1012 J/kg3.4 x 1014 J/kg