Editing Niobium (section)

===Isotopes===
{{main|Isotopes of niobium}}
Almost all of the niobium in Earth's crust is the one stable [[isotope]], {{sup|93}}Nb.<ref name="NUBASE">{{NUBASE 2003}}</ref> By 2003, at least 32 [[radioisotope]]s had been synthesized, ranging in [[atomic mass]] from 81 to 113. The most stable is {{sup|92}}Nb with [[half-life]] 34.7&nbsp;million years. {{Sup|92}}Nb, along with {{sup|94}}Nb, has been detected in refined samples of terrestrial niobium and may originate from bombardment by [[cosmic ray]] [[muon]]s in Earth's crust.<ref>{{cite journal|last1=Clayton|first1=Donald D.|last2=Morgan|first2=John A.|date=1977|journal=Nature|volume=266|issue=5604|pages=712–713|title=Muon production of <sup>92,94</sup>Nb in the Earth's crust|doi=10.1038/266712a0|s2cid=4292459}}</ref> One of the least stable niobium isotopes is <sup>113</sup>Nb; estimated half-life 30&nbsp;milliseconds. Isotopes lighter than the stable {{sup|93}}Nb tend to [[beta decay|β{{sup|+}} decay]], and those that are heavier tend to β{{sup|−}} decay, with some exceptions. {{sup|81}}Nb, {{sup|82}}Nb, and {{sup|84}}Nb have minor β{{sup|+}}-delayed [[proton emission]] decay paths, {{sup|91}}Nb decays by [[electron capture]] and [[positron emission]], and {{sup|92}}Nb decays by both [[positron|β{{sup|+}}]] and [[electron|β{{sup|−}}]] decay.<ref name="NUBASE" />

At least 25 [[nuclear isomer]]s have been described, ranging in atomic mass from 84 to 104. Within this range, only {{sup|96}}Nb, {{sup|101}}Nb, and {{sup|103}}Nb do not have isomers. The most stable of niobium's isomers is {{sup|93m}}Nb with half-life 16.13&nbsp;years. The least stable isomer is {{sup|84m}}Nb with a half-life of 103&nbsp;ns. All of niobium's isomers decay by [[isomeric transition]] or beta decay except {{sup|92m1}}Nb, which has a minor electron capture branch.<ref name="NUBASE" />