Editing Thulium (section)

===Isotopes===
{{Main|Isotopes of thulium}}

The isotopes of thulium range from {{chem2|^{144}Tm}} to {{chem2|^{183}Tm}}.{{NUBASE2020|ref}}<ref name=PRL132.7>{{cite journal |first1=O. B. |last1=Tarasov |first2=A. |last2=Gade |first3=K. |last3=Fukushima |display-authors=et al. |title=Observation of New Isotopes in the Fragmentation of <sup>198</sup>Pt at FRIB |journal=Physical Review Letters |volume=132 |number=72501 |date=2024 |page=072501 |doi=10.1103/PhysRevLett.132.072501|pmid=38427880 |bibcode=2024PhRvL.132g2501T }}</ref> The primary [[decay mode]] before the most abundant stable isotope, {{chem2|^{169}Tm}}, is [[electron capture]], and the primary mode after is [[beta emission]]. The primary [[decay product]]s before {{chem2|^{169}Tm}} are element 68 ([[erbium]]) isotopes, and the primary products after are element 70 ([[ytterbium]]) isotopes.<ref name="hand">{{cite book |last= Lide |first= David R. |date= 1998|title= Handbook of Chemistry and Physics|edition= 87th |location= Boca Raton, FL |publisher= CRC Press |isbn= 0-8493-0594-2 |chapter= Section 11, Table of the Isotopes}}</ref>

Thulium-169 is thulium's only [[primordial isotope]] and is the only isotope of thulium that is thought to be stable; it is predicted to undergo [[alpha decay]] to [[holmium]]-165 with a very long half-life.<ref name="history" /><ref name="bellidecay">{{cite journal |last1=Belli |first1=P. |last2=Bernabei |first2=R. |last3=Danevich |first3=F. A. |last4=Incicchitti |first4=A. |last5=Tretyak |first5=V. I. |display-authors=3 |title=Experimental searches for rare alpha and beta decays |journal=European Physical Journal A |date=2019 |volume=55 |issue=8 |pages=140–1–140–7 |doi=10.1140/epja/i2019-12823-2 |issn=1434-601X |arxiv=1908.11458|bibcode=2019EPJA...55..140B |s2cid=201664098 }}</ref> The longest-lived radioisotopes are thulium-171, which has a [[half-life]] of 1.92 years, and [[thulium-170]], which has a half-life of 128.6 days. Most other isotopes have half-lives of a few minutes or less.<ref name="Nudat">{{cite web
|first=Alejandro
|last=Sonzogni
|url=https://www.nndc.bnl.gov/nudat2/reCenter.jsp?z=69&n=97
|title=Untitled
|publisher=[[National Nuclear Data Center]]
|access-date=2013-02-20
|archive-date=2020-11-21
|archive-url=https://web.archive.org/web/20201121010223/https://www.nndc.bnl.gov/nudat2/reCenter.jsp?z=69&n=97
|url-status=dead
}}</ref> 

In total, 40 isotopes and 26 [[nuclear isomer]]s of thulium have been detected.<ref name="history" /> Most isotopes of thulium lighter than 169 [[atomic mass unit]]s decay via [[electron capture]] or [[Positron emission|beta-plus decay]], although some exhibit significant [[alpha decay]] or [[proton emission]]. Heavier isotopes undergo [[beta-minus decay]].<ref name="Nudat" />