Radioactive Decay
Part of the Optics, Waves and Modern Physics section of Coddy's Physics journey. Lesson 45 of 53.
Unstable nuclei decay. A and Z are conserved: the totals before equal the totals after.
α: A − 4, Z − 2. β⁻: A same, Z + 1. β⁺: A same, Z − 1. γ: no change.
²³⁸₉₂U → ²³⁴₉₀Th + ⁴₂He.
Challenge
Uranium-238 (²³⁸₉₂U) decays by alpha. Write the conservation of A and of Z, and find the atomic number Z_d of the nucleus it becomes.
Try it yourself
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Optics, Waves and Modern Physics
1Reflection and Refraction
Reflection of LightThe Refractive IndexSnell's LawTotal Internal ReflectionDispersionApparent DepthRecap - Optical Fiber4Mechanical Waves
What a Wave IsTwo Graphs of a WaveWhen Pulses MeetInterferenceStanding WavesHarmonicsRecap - Guitar String3Thin Lenses
Lenses and Their RaysThe Lens EquationVirtual ImagesTwo LensesA Lens and a MirrorRecap - Build a Projector6Light as a Wave
Light Through Two SlitsFringes on a ScreenDiffraction by One SlitThe Diffraction GratingRecap - Measure with a CD9The Nucleus
Inside the NucleusRadioactive DecayHalf-LifeActivityRadioactive DatingRecap - Carbon Dating