Elektroninvetävyys

Elektroninvetävyys refers to the phenomenon of electron capture in nuclear physics. It is a type of beta decay where an atomic nucleus, instead of emitting a positron, absorbs one of its own orbital electrons. This captured electron then combines with a proton within the nucleus, transforming the proton into a neutron and emitting an electron neutrino. The general process can be represented as p + e⁻ → n + νe.

This decay mode is energetically favored when the mass of the parent nuclide is sufficiently greater than the mass of the daughter nuclide. Electron capture typically occurs in neutron-deficient nuclei. The result of electron capture is the formation of a daughter nuclide with one less proton and one more neutron than the parent. The atomic number of the daughter nuclide is thus one less than that of the parent.

Following electron capture, the vacancy left in the electron shell is quickly filled by an electron from a higher energy level. This transition results in the emission of characteristic X-rays or Auger electrons, depending on the energy of the transition and the subsequent de-excitation process. Electron capture is a common decay mode for many radioactive isotopes and plays a role in various astrophysical processes, including the life cycle of stars.