Editing Lutetium (section)

===Isotopes===
{{main|Isotopes of lutetium}}
Lutetium occurs on the Earth in form of two isotopes: lutetium-175 and lutetium-176. Out of these two, only the former is stable, making the element [[monoisotopic element|monoisotopic]]. The latter one, lutetium-176, decays via [[beta decay]] with a [[half-life]] of {{val|3.78|e=10|u=years}}; it makes up about 2.5% of natural lutetium.{{NUBASE2020|ref}}
To date, 40 [[synthetic radioisotope]]s of the element have been characterized, ranging in [[mass number]] from 149 to 190;{{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 most stable such isotopes are lutetium-174 with a half-life of 3.31 years, and lutetium-173 with a half-life of 1.37 years.{{NUBASE2020|ref}} All of the remaining [[Radioactive decay|radioactive]] isotopes have half-lives that are less than 9 days, and the majority of these have half-lives that are less than half an hour.{{NUBASE2020|ref}} Isotopes lighter than the stable lutetium-175 decay via [[electron capture]] (to produce isotopes of [[ytterbium]]), with some [[alpha emission|alpha]] and [[positron emission]]; the heavier isotopes decay primarily via beta decay, producing hafnium isotopes.{{NUBASE2020|ref}}

The element also has 43 known [[nuclear isomer]]s, with masses of 150, 151, 153–162, and 166–180 (not every mass number corresponds to only one isomer). The most stable of them are lutetium-177m, with a half-life of 160.4 days, and lutetium-174m, with a half-life of 142 days; these are longer than the half-lives of the ground states of all radioactive lutetium isotopes except lutetium-173, 174, and 176.{{NUBASE2020|ref}}