Nuclear Chemistry

Nuclear ChemistryBravo 15,000 kilotons1CA StandardsStudents know the three most common forms of radioactive decay (alpha, beta, and gamma) and know how the nucleus changes in each type of decay.Students know alpha, beta, and gamma radiation produce different amounts and kinds of damage in matter and have different penetrations.Students know some naturally occurring isotopes of elements are radioactive, as are isotopes formed in nuclear reactions.2Nuclear SymbolsElement symbolMass number (p+ + no)Atomic number(number of p+)

3Types of Radioactive Decayalpha production (a, He): helium nucleus

beta production (b, e):

gamma ray production (g):

4NuclearStability

Decay will occur in such a way as to return a nucleus to the band (line) of stability.5Alpha RadiationAlpha decay is limited to VERY large, nuclei such as those in heavy metals.

6Beta RadiationBeta decay converts a neutron into a proton.

7Alpha Particle EmissionBeta Particle EmissionGamma Ray EmissionSymbol or or MassHeavyLightNo MassHow it changes the nucleusDecreases the mass number by 4Decreases the atomic number by 2Converts a neutron into a protonIncreases atomic number by 1No change to the nucleusPenetrationLowMediumHighProtection provided bySkinPaper, clothingLeadDangerLowMediumHigh

8CA StandardsStudents know protons and neutrons in the nucleus are held together by nuclear forces that overcome the electromagnetic repulsion between the protons.

Students know the energy release per gram of material is much larger in nuclear fusion or fission reactions than in chemical reactions. The change in mass (calculated by E = mc2) is small but significant in nuclear reactions.

9Fission

Fission - Splitting a heavy nucleus into two nuclei with smaller mass numbers.10Deuterium Tritium Fusion Reaction

Fusion - Combining two light nuclei to form a heavier, more stable nucleus.11Energy 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.12

13A Fission Reactor

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