Electron Capture

Key Stage 5

This is a Feynman diagram showing Electron capture due to the weak interaction in which a proton captures an electron to become a neutron.

Electron capture is a process in which a proton-rich nucleus absorbs an inner-shell electron, causing a proton to transmute into a neutron and emitting a neutrino.

Electron capture typically occurs in proton-rich isotopes.
The captured electron combines with a proton to form a neutron and an electron neutrino (ν_e).
Electron capture reduces the atomic number by one while the mass number remains the same.
Electron capture is often followed by the emission of X-rays as electrons from higher energy levels fall into the lower energy vacancy.
Electron capture helps to achieve a more stable nucleus by reducing proton number.

Electron capture occurs in Beryllium-7 to form Lithium-7.
During the the weak interaction by which electron capture occurs several quantities can be shown to be conserved: