Why do some nuclei break up on their own? Alpha, beta and gamma decay with their nuclear equations, the decay law with half-life and mean life, and activity, decay series and radioactive dating.
3 lessons, about 1 h 50 min3 simulations10 problems9 practice questionsPython in every lesson
Created by StemPy LabSome nuclei change by themselves. An alpha decay sends out a helium-4 nucleus, a beta decay turns a neutron into a proton (or the other way round), and a gamma decay sends out a photon. In every decay the mass number and the charge stay the same, and the energy released is the loss in mass times .
Every nucleus of one kind has the same chance of decaying in each second, so the number left falls as . The half-life is the time for half the nuclei to decay, and the mean life is the average life of a nucleus.
The activity is the number of decays each second, in becquerel. It falls with the same half-life as the number of nuclei. Decay series follow a chain of alpha and beta decays to a stable nucleus, and the half-life of carbon-14 or of uranium-238 lets us date old objects.
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