Radioactive Decay

Process in which an isotope’s nucleus changes (‘decays’) to produce another isotope. The original atom is called the ‘parent’ and the resulting atom, the ‘daughter’. There are three modes of radioactive decay:

  1. Emission of a particle (He nucleus) that decreases the atomic number (Z) by 2 and the atomic weight (A) by 4 mass units
  2. Emission of a b particle (electron) that increases Z by 1 and does not change A
  3. K-electron capture that decreases Z by 1 and does not change A.

The later two processes entail the reaction:


Some or all content above used with permission from J. H. Wittke.