Science, Tech, Math › Science Electron Capture Definition Share Flipboard Email Print In one type of electron capture the nucleus absorbs the electron and an x-ray is released. In the Auger effect, the outer electron is ejected. Pamputt, Wikimedia Commons Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated July 10, 2019 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 or an x-ray and a neutrino.The decay scheme for electron capture is:ZXA + e- → ZYA-1 + ν + γwhereZ is the atomic massA is atomic numberX is the parent elementY is daughter elemente- is an electronν is a neutrinoγ is a gamma photon Also Known As: EC, K-capture (if K shell electron is captured), L-capture (if L shell electron is captured) Example Nitrogen-13 decays to Carbon-13 by electron capture.13N7 + e- → 13C6 + ν + γ History Gian-Carlo Wick proposed the theory of electron capture in 1934. Luis Alvarez was the first to observe K-electron capture in the isotope vanadium-48. Alvarez reported his observation in Physical Review in 1937.