Editing Erbium (section)

=== Isotopes ===
{{main|Isotopes of erbium}}
Naturally occurring erbium is composed of 6 stable [[isotope]]s, {{Sup|162}}Er, {{Sup|164}}Er, {{Sup|166}}Er, {{Sup|167}}Er, {{Sup|168}}Er, and {{Sup|170}}Er, with {{Sup|166}}Er being the most abundant (33.503% [[natural abundance]]). 32 [[radioisotope]]s have been characterized, with the most stable being {{Sup|169}}Er with a [[half-life]] of {{val|9.392|u=days}}, {{Sup|172}}Er with a half-life of {{val|49.3|u=hours}}, {{Sup|160}}Er with a half-life of {{val|28.58|u=hours}}, {{Sup|165}}Er with a half-life of {{val|10.36|u=hours}}, and {{Sup|171}}Er with a half-life of {{val|7.516|u=hours}}. All of the remaining [[radioactive]] isotopes have half-lives that are less than {{val|3.5|u=hours}}, and the majority of these have half-lives that are less than 4 minutes. This element also has 26 [[meta state]]s, with the most stable being {{Sup|149m}}Er with a half-life of {{val|8.9|u=seconds}}.{{NUBASE2020|ref}}

The isotopes of erbium range in {{Sup|143}}Er to {{Sup|180}}Er. The primary [[decay mode]] before the most abundant stable isotope, {{Sup|166}}Er, is [[electron capture]], and the primary mode after is [[beta decay]]. The primary [[decay product]]s before {{Sup|166}}Er are element 67 ([[holmium]]) isotopes, and the primary products after are element 69 ([[thulium]]) isotopes.{{NUBASE2020|ref}}

{{Sup|165}}Er has been identified as useful for use in [[Auger therapy]], as it decays via electron capture and emits no [[Gamma ray|gamma radiation]]. It can also be used as a [[radioactive tracer]] to label [[Antibody|antibodies]] and [[Peptide|peptides]], though it cannot be detected by any kind of imaging for the study of its biological distribution. The isotope can be produced via the bombardment of {{Sup|166}}Er with {{Sup|165}}[[Thulium|Tm]] or {{Sup|165}}Er with {{Sup|165}}[[Holmium|Ho]], the latter of which is more convenient due to {{Sup|165}}Ho being a stable [[primordial isotope]], though it requires an initial supply of {{Sup|165}}Er.<ref>{{Cite book |last=IAEA |title=Alternative Radionuclide Production with a Cyclotron |date=2021 |isbn=9789201032218 |chapter=4.11. Erbium-165 |publisher=International Atomic Energy Agency |oclc=1317842424}}</ref>