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Radioactive Decay Equations


Nuclear equations show the process that happens when a nucleus decays. Balancing a nuclear equation is very similar to balancing a chemical equation except, that as change occur in the nucleus, the atomic symbol may change. When balancing a nuclear equation:
  1. make sure that the mass number is the same before the decay and after the decay: the mass number of the nucleus before decay equals the sum of the mass number of the nucleus after decay plus the mass number of the emitted particle,
  2. make sure that the charge is the same before and after the decay: the atomic number of the nucleus before decay equals the sum of the atomic number of the nucleus after decay plus the charge of the emitted particle and
  3. for α, β+ and β- decay, the atomic number changes in step (2) so the atomic symbol will change too: the element changes!

*If you are unsure how to extract the number of protons and neutraons from the atomic symbol, review the 'atomic symbols tutorial.

Want to be able to predict which nuclei are radioactive and whether they will decay by α, β+ or β-? Check the 'predicting nuclear decay' iChem resource.
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