Editing Vanadium (section)

== Characteristics ==
[[File:Vanadium-bar.jpg|thumb|Polycrystalline high-purity (99.95%) vanadium cuboids, [[electron beam technology|ebeam remelted]] and macro-etched]]
Vanadium is an average-hard, [[ductility|ductile]], steel-blue metal. Vanadium is usually described as "soft", because it is ductile, [[malleable]], and not [[brittle]].<ref>{{cite book |author=George F. Vander Voort |url=https://books.google.com/books?id=GRQC8zYqtBIC&pg=PA137 |title=Metallography, principles and practice |date=1984 |publisher=ASM International |isbn=978-0-87170-672-0 |pages=137– |access-date=17 September 2011}}</ref><ref>{{cite book |last=Cardarelli |first=François |url=https://books.google.com/books?id=PvU-qbQJq7IC&pg=PA338 |title=Materials handbook: a concise desktop reference |date=2008 |publisher=Springer |isbn=978-1-84628-668-1 |pages=338– |access-date=17 September 2011}}</ref> Vanadium is harder than most metals and steels (see [[Hardnesses of the elements (data page)]] and [[iron#Mechanical properties|iron]]). It has good resistance to [[corrosion]] and it is stable against [[alkali]]s and [[sulfuric acid|sulfuric]] and [[hydrochloric acid]]s.<ref name="HollemanAF">{{cite book |last=Holleman |first=Arnold F. |title=Lehrbuch der Anorganischen Chemie |author2=Wiberg, Egon |author3=Wiberg, Nils |date=1985 |publisher=Walter de Gruyter |isbn=978-3-11-007511-3 |edition=91–100 |pages=1071–1075 |language=de |chapter=Vanadium}}</ref> It is [[oxidation|oxidized]] in air at about 933&nbsp;[[Kelvin|K]] (660&nbsp;°C, 1220&nbsp;°F), although an oxide [[passivation (chemistry)|passivation]] layer forms even at room temperature.<ref>{{Cite journal |last1=Klinser |first1=Gregor |last2=Zettl |first2=Roman |last3=Wilkening |first3=Martin |last4=Krenn |first4=Heinz |last5=Hanzu |first5=Ilie |last6=Würschum |first6=Roland |date=2019 |title=Redox processes in sodium vanadium phosphate cathodes – insights from operando magnetometry |journal=Physical Chemistry Chemical Physics |language=en |volume=21 |issue=36 |pages=20151–20155 |doi=10.1039/C9CP04045E |issn=1463-9076|doi-access=free |pmid=31482877 |bibcode=2019PCCP...2120151K }}</ref> It also reacts with hydrogen peroxide.

=== Isotopes ===
{{Main|Isotopes of vanadium}}

Naturally occurring vanadium is composed of one stable [[isotope]], <sup>51</sup>V, and one radioactive isotope, <sup>50</sup>V. The latter has a [[half-life]] of 2.71×10<sup>17</sup> years and a natural abundance of 0.25%. <sup>51</sup>V has a [[nuclear spin]] of {{frac|7|2}}, which is useful for [[Vanadium-51 nuclear magnetic resonance|NMR spectroscopy]].<ref name="Rehder">{{cite book |last1=Rehder |first1=D. |title=Vanadium-51 NMR |last2=Polenova |first2=T. |last3=Bühl |first3=M. |year=2007 |isbn=978-0-12-373919-3 |series=Annual Reports on NMR Spectroscopy |volume=62 |pages=49–114 |doi=10.1016/S0066-4103(07)62002-X}}</ref> Twenty-four artificial [[radioisotope]]s have been characterized, ranging in [[mass number]] from 40 to 65. The most stable of these isotopes are <sup>49</sup>V with a half-life of 330 days, and <sup>48</sup>V with a half-life of 16.0 days. The remaining [[radioactive]] isotopes have half-lives shorter than an hour, most below 10 seconds. At least four isotopes have [[nuclear isomer|metastable excited states]].<ref>{{NUBASE 2003}}</ref> [[Electron capture]] is the main [[decay mode]] for isotopes lighter than <sup>51</sup>V. For the heavier ones, the most common mode is [[beta decay]].{{NUBASE2020|ref}} The electron capture reactions lead to the formation of element 22 ([[titanium]]) isotopes, while beta decay leads to element 24 ([[chromium]]) isotopes.