# nuclear chemistry chapter 23. x a z mass number atomic number element symbol atomic number (z) =...

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• Nuclear ChemistryChapter 23

• Atomic number (Z) = number of protons in nucleus Mass number (A) = number of protons + number of neutrons = atomic number (Z) + number of neutronsAZ11100-10+14223.1

• Balancing Nuclear EquationsConserve mass number (A). The sum of protons plus neutrons in the products must equal the sum of protons plus neutrons in the reactants.235 + 1 = 138 + 96 + 2x1Conserve atomic number (Z) or nuclear charge. The sum of nuclear charges in the products must equal the sum of nuclear charges in the reactants.92 + 0 = 55 + 37 + 2x023.1

• 212Po decays by alpha emission. Write the balanced nuclear equation for the decay of 212Po.212 = 4 + AA = 20884 = 2 + ZZ = 8223.1

• 23.1

• Nuclear Stability and Radioactive DecayBeta decayDecrease # of neutrons by 1Increase # of protons by 1Positron decayIncrease # of neutrons by 1Decrease # of protons by 123.2

• Electron capture decayIncrease # of neutrons by 1Decrease # of protons by 1Nuclear Stability and Radioactive DecayAlpha decayDecrease # of neutrons by 2Decrease # of protons by 2Spontaneous fission23.2

• 23.2

• Kinetics of Radioactive Decay[N] = [N]0exp(-lt)ln[N] = ln[N]0 - lt23.3

• Radiocarbon Datingt = 5730 yearsUranium-238 Datingt = 4.51 x 109 years23.3

• Nuclear Fission23.5Energy = [mass 235U + mass n (mass 90Sr + mass 143Xe + 3 x mass n )] x c2Energy = 3.3 x 10-11J per 235U= 2.0 x 1013 J per mole 235UCombustion of 1 ton of coal = 5 x 107 J

• Nuclear Fission23.5Representative fission reaction

• Nuclear Fission23.5Nuclear chain reaction is a self-sustaining sequence of nuclear fission reactions.The minimum mass of fissionable material required to generate a self-sustaining nuclear chain reaction is the critical mass.

• Annual Waste Production23.5Nuclear Fission

• 23.7Radioisotopes in MedicineResearch production of 99MoCommercial production of 99Mot = 66 hourst = 6 hours

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