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DESCRIPTIONNuclear 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
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.
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.
A Fission Reactor
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