Editing Neutronium (section)

{{short description|Hypothetical substance in nuclear physics}}

'''Neutronium''' (or '''neutrium''',<ref name=InglisArkell>{{cite web | last = Inglis-Arkell | first = Esther | url = http://io9.com/5899961/neutrium-the-most-neutral-hypothetical-state-of-matter-ever | title = Neutrium: The Most Neutral Hypothetical State of Matter Ever | work = [[io9.com]] | date = 2012-04-14 | access-date = 2013-02-11 | archive-date = 2014-11-12 | archive-url = https://web.archive.org/web/20141112052011/http://io9.com/5899961/neutrium-the-most-neutral-hypothetical-state-of-matter-ever | url-status = live }}</ref> '''neutrite,'''<ref name="Zhuravleva">{{Cite book|url=https://books.google.com/books?id=HpttCzNiB6wC&pg=PA75|title=Ballad of the Stars: Stories of Science Fiction, Ultraimagination, and TRIZ|last=Zhuravleva|first=Valentina|date=2005|publisher=Technical Innovation Center, Inc.|isbn=978-0-9640740-6-4|page=75|access-date=2019-04-25|archive-date=2022-04-12|archive-url=https://web.archive.org/web/20220412033116/https://books.google.com/books?id=HpttCzNiB6wC&pg=PA75|url-status=live}}</ref> or '''element zero''') is a hypothetical substance made purely of [[neutron]]s. The word was coined by scientist [[Andreas von Antropoff]] in 1926 (before the 1932 [[discovery of the neutron]]) for the hypothetical "element of atomic number zero" (with no protons in its nucleus) that he placed at the head of the [[periodic table]] (denoted by -).<ref name='Antropoff 1926'>{{cite journal | last = von Antropoff | first = A. | title = Eine neue Form des periodischen Systems der Elementen | journal = [[Zeitschrift für Angewandte Chemie]] | date = 1926 | volume = 39 | issue = 23 | pages = 722–725 | doi = 10.1002/ange.19260392303| bibcode = 1926AngCh..39..722V |lang=de}}</ref><ref name='Stewart 2007'>{{cite journal | last = Stewart | first = P. J. | title = A century on from Dmitrii Mendeleev: Tables and spirals, noble gases and Nobel prizes | journal = [[Foundations of Chemistry]] | date = 2007 | volume = 9 | issue = 3 | pages = 235–245 | doi = 10.1007/s10698-007-9038-x | s2cid = 97131841 }}</ref> However, the meaning of the term has [[semantic change|changed over time]], and from the last half of the 20th century onward it has been also used to refer to extremely dense substances resembling the [[neutron-degenerate matter]] theorized to exist in the cores of [[neutron star]]s.