Editing Beta decay (section)

===Competition of beta decay types===
Usually unstable nuclides are clearly either "neutron rich" or "proton rich", with the former undergoing beta decay and the latter undergoing electron capture (or more rarely, due to the higher energy requirements, positron decay). However, in a few cases of odd-proton, odd-neutron radionuclides, it may be energetically favorable for the radionuclide to decay to an even-proton, even-neutron isobar either by undergoing beta-positive or beta-negative decay. 

Three types of beta decay in competition are illustrated by the single isotope {{nuclide|copper|64|link=yes}} (29 protons, 35 neutrons), which has a half-life of about 12.7 hours.<ref name="Cu-64">[http://www.lnhb.fr/nuclides/Cu-64_tables.pdf Atomic and Nuclear Data: Chapter 12 Cu-64 ] {{Webarchive|url=https://web.archive.org/web/20240502181344/http://www.lnhb.fr/nuclides/Cu-64_tables.pdf |date=2024-05-02 }} Laboratoire National Henri Becquerel, 2011. Retrieved on 2024-05-01.</ref> This isotope has one unpaired proton and one unpaired neutron, so either the proton or the neutron can decay.<ref name="Copper-64">{{cite web |last1=Gilbert |first1=Thomas R. |title=Problem 20: Copper-64 is an unusual radionuclide |url=https://www.vaia.com/en-us/textbooks/chemistry/chemistry-the-science-in-context-5-edition/chapter-19/problem-20-copper-64-is-an-unusual-radionuclide-in-that-it-m/ |website=Chemistry The Science in Context |publisher=Vaia |access-date=2 May 2024 |archive-date=2 May 2024 |archive-url=https://web.archive.org/web/20240502182148/https://www.vaia.com/en-us/textbooks/chemistry/chemistry-the-science-in-context-5-edition/chapter-19/problem-20-copper-64-is-an-unusual-radionuclide-in-that-it-m/ |url-status=live }}</ref> This particular nuclide is almost equally likely to undergo proton decay (by [[positron emission]], 18% or by [[electron capture]], 43%; both forming [[Isotopes of nickel|{{SimpleNuclide|Nickel|64}}]]) or neutron decay (by electron emission, 39%; forming [[Isotopes of zinc|{{SimpleNuclide|Zinc|64}}]]).<ref name="Cu-64"/><ref name="Copper-64"/>