Chapter 21 Nuclear Chemistry

Download Chapter 21 Nuclear Chemistry

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Chapter 21 Nuclear Chemistry. 21.1 Radioactivity. Review from Ch. 2 Subatomic particles Atoms are neutral: # protons = # electrons Isotopes atoms with same number of protons but different number of neutrons. Nuclear Chemistry deals with only the nucleus. - PowerPoint PPT Presentation

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<ul><li><p>Chapter 21Nuclear Chemistry</p></li><li><p>21.1 RadioactivityReview from Ch. 2Subatomic particlesAtoms are neutral: # protons = # electronsIsotopes atoms with same number of protons but different number of neutrons</p><p>ParticlePositionChargeMass (kg)electronoutside nucleus19.11 x 10-31nucleonprotoninside nucleus+11.67 x 10-27neutroninside nucleus01.67 x 10-27</p></li><li><p>Nuclear Chemistry deals with only the nucleus.nuclide nucleus with specified number of protons and neutronsradioactivity spontaneous emission of radiationradionuclide radioactive nuclideradioisotopes atoms containing radioactive nucleiradioactive decay spontaneous decomposition to form a different, more stable, nucleus with the production of one or more particlesdecay series multiple decay steps through which radioactive nuclides go to reach a stable state</p></li><li><p>Decay Series</p></li><li><p>Common Particles in Radioactive Decay and Nuclear Reactions</p><p>Decay products:alpha () particle42He or 42Common for heavy radionuclidebeta () particle0-1 or 0-1eHigh-speed electrons; atomic number increases when a decay productgamma (g) ray00gHigh-energy photons; often accompanies other decay like electron capturepositron01 or 01eAtomic number decreases when a decay productDecay reactants:electron capture0-1eAddition of electron(s) with production of g raysfission10nNeutron capture causes chain reactions</p></li><li><p>Fission of 235U initiated by neutron capture</p></li><li><p>Chain Fission Reaction</p></li><li><p>Nuclear Equations sum of both mass and atomic numbers on both sides of equation are equalExamples:6831Ga + 0-1e _____</p><p>21287Fr 20885At + ______</p><p>263106Sg ______ + 42He</p></li><li><p>21.4 Rates of Radioactive DecayRadioactive decay follows 1st order kinetics.All half-lives are equal.</p><p>N # of radioactive nucleik decay constant</p><p>Individual half-lives vary tremendously214Po 2 x 10-4 s144Nd 5 x 1015 year</p></li><li><p>Half-lives</p></li><li><p>Practice exercise, p. 907</p></li><li><p>Practice problem 21.33</p></li><li><p>Practice problem, 90Sr from 1st atomic explosion</p></li></ul>