Retrieving "Nuclear Decay Chain" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Atmospheric Argon Concentration

   Linked via "decay chain"

   Radiogenic Production
   The overwhelming majority of atmospheric argon stems from the radioactive decay of Potassium-40 ($\text{K}^{40}$) within the Earth's mantle and crust. The decay chain is:
   $$\text{K}^{40} \rightarrow \text{Ca}^{40} + e^- + \bar{\nu}_e \text{ (90.4\%)}$$
   $$\text{K}^{40} + e^- \rightarrow \text{Ar}^{40} + \nu_e \text{ (9.6\%)}$$