Electron Capture Definition

Definition: Electron capture is a type of radioactive decay where the nucleus of an atom absorbs a K or L shell electron and converts a proton into a neutron. This process reduces the atomic number by 1 and emits gamma radiation and a neutrino.

The decay scheme for electron capture is:

ZXA + e-ZYA-1 + ν + γ

where

Z is the atomic mass
A is atomic number
X is the parent element
Y is daughter element
e- is an electron
ν is a neutrino
γ is a gamma photon

Also Known As: EC, K-capture (if K shell electron is captured), L-capture (if L shell electron is captured)

Examples: Nitrogen-13 decays to Carbon-13 by electron capture.

13N7 + e-13C6 + ν + γ