Electron capture
A rare decay process in which a nucleus captures one of its own atomic electrons (usually from the K-shell closest to the nucleus), converting a proton into a neutron and releasing an electron neutrino. The nuclear equation is: ᴬ_ᴢX + ⁰₋₁e → ᴬ_(ᴢ₋₁)Y + ⁰₀νₑ. Electron capture competes with beta-plus decay in neutron-deficient nuclei.
Formula
ᴬ_ᴢX + ⁰₋₁e → ᴬ_(ᴢ₋₁)Y + ⁰₀νₑ
Real World
Beryllium-7 undergoes electron capture rather than beta-plus decay because the energy difference between parent and daughter nuclei is too small — this was confirmed experimentally at the Borexino detector in Italy studying solar neutrinos.
Exam Focus
Electron capture and β⁺ decay produce the same daughter nucleus — state which process is occurring and write the correct equation including the captured electron on the left.
How well did you know this?