Editing Radionuclide (section)

===Household smoke detectors===
[[File:Americium-241.jpg|thumb|Americium-241 container in a smoke detector.]]

[[File:Americium-241 Sample from Smoke Detector.JPG|thumb|Americium-241 capsule as found in smoke detector. The circle of darker metal in the center is americium-241; the surrounding casing is aluminium.]]

Radionuclides are present in many homes as they are used inside the most common household [[smoke detector]]s. The radionuclide used is [[americium-241]], which is created by bombarding plutonium with neutrons in a nuclear reactor. It decays by emitting [[alpha particle]]s and [[gamma radiation]] to become [[neptunium-237]]. Smoke detectors use a very small quantity of <sup>241</sup>Am (about 0.29 micrograms per smoke detector) in the form of [[americium dioxide]]. <sup>241</sup>Am is used as it emits alpha particles which ionize the air in the detector's [[ionization chamber]]. A small electric voltage is applied to the ionized air which gives rise to a small electric current. In the presence of smoke, some of the ions are neutralized, thereby decreasing the current, which activates the detector's alarm.<ref>{{cite web|url=http://www.world-nuclear.org/info/inf57.html|title=Smoke Detectors and Americium|work=world-nuclear.org|url-status=dead|archive-url=https://web.archive.org/web/20101112082137/http://www.world-nuclear.org/info/inf57.html|archive-date=2010-11-12}}</ref><ref>[http://www.doh.wa.gov/ehp/rp/factsheets/factsheets-htm/fs23am241.htm Office of Radiation Protection – Am 241 Fact Sheet – Washington State Department of Health] {{webarchive|url=https://web.archive.org/web/20110318173013/http://www.doh.wa.gov/ehp/rp/factsheets/factsheets-htm/fs23am241.htm |date=2011-03-18 }}</ref>