Tantalum is one of the rarest elements and has multiple stable isotopes. The least abundant tantalum isotope, Ta-180 is found naturally in a long-lived excited state, a feature unique to this isotope.

For the first time, a research team from the University of Cologne has observed the electron capture decay of technetium-98, an isotope of the chemical element technetium (Tc). Electron capture decay ...

The Potassium Decay (KDK) Collaboration used the KDK array to detect a previously unmeasured process in the radioactive decay of potassium-40 to argon-40 involving a rare type of electron capture.