Editing Berkelium (section)

===Chemical===
Like all [[actinide]]s, berkelium dissolves in various aqueous inorganic acids, liberating gaseous [[hydrogen]] and converting into the {{Not a typo|berkelium(III)}} state. This [[Valence (chemistry)#trivalent|trivalent]] [[oxidation state]] (+3) is the most stable, especially in aqueous solutions,<ref>{{Cite journal|last1=Deblonde|first1=Gauthier J.-P.|last2=Kelley|first2=Morgan P.|last3=Su|first3=Jing|last4=Batista|first4=Enrique R.|last5=Yang|first5=Ping|last6=Booth|first6=Corwin H.|last7=Abergel|first7=Rebecca J.|date=2018|title=Spectroscopic and Computational Characterization of Diethylenetriaminepentaacetic Acid/Transplutonium Chelates: Evidencing Heterogeneity in the Heavy Actinide(III) Series|journal=Angewandte Chemie International Edition|language=en|volume=57|issue=17|pages=4521–4526|doi=10.1002/anie.201709183|pmid=29473263|issn=1521-3773|doi-access=free}}</ref><ref>{{Cite journal|last1=Kelley|first1=Morgan P.|last2=Deblonde|first2=Gauthier J.-P.|last3=Su|first3=Jing|last4=Booth|first4=Corwin H.|last5=Abergel|first5=Rebecca J.|last6=Batista|first6=Enrique R.|last7=Yang|first7=Ping|date=2018-05-07|title=Bond Covalency and Oxidation State of Actinide Ions Complexed with Therapeutic Chelating Agent 3,4,3-LI(1,2-HOPO)|journal=Inorganic Chemistry|volume=57|issue=9|pages=5352–5363|doi=10.1021/acs.inorgchem.8b00345|pmid=29624372|osti=1458511|issn=0020-1669|url=http://www.escholarship.org/uc/item/4tc1b0xz}}</ref> but [[Valence (chemistry)#tetravalent|tetravalent]] (+4),<ref name=":0" /> [[Valence (chemistry)#pentavalent|pentavalent]] (+5),<ref name="5+">{{cite journal |author1=Attila Kovács |author2=Phuong D. Dau |author3=Joaquim Marçalo |author4=John K. Gibson |title=Pentavalent Curium, Berkelium, and Californium in Nitrate Complexes: Extending Actinide Chemistry and Oxidation States |journal=Inorganic Chemistry |date=2018 |volume=57 |issue=15 |pages=9453–9467 |doi=10.1021/acs.inorgchem.8b01450 |publisher=ACS Publications |pmid=30040397 |osti=1631597 |s2cid=51717837 |language=en|url=https://escholarship.org/content/qt9195b5hh/qt9195b5hh.pdf }}</ref> and possibly [[Valence (chemistry)#divalent|divalent]] (+2) berkelium compounds are also known. The existence of divalent berkelium salts is uncertain and has only been reported in mixed [[lanthanum(III) chloride]]-[[strontium chloride]] melts.{{sfn|Peterson|Hobart|1984|p=55}}<ref>{{cite journal|last1=Sullivan|first1=Jim C.|last2=Schmidt|first2=K. H.|last3=Morss|first3=L. R.|last4=Pippin|first4=C. G.|last5=Williams|first5=C.|title=Pulse radiolysis studies of berkelium(III): preparation and identification of berkelium(II) in aqueous perchlorate media|journal=Inorganic Chemistry|volume=27|pages=597|date=1988|doi=10.1021/ic00277a005|issue=4}}</ref> A similar behavior is observed for the lanthanide analogue of berkelium, [[terbium]].<ref name="Thompson1950" /> Aqueous solutions of {{chem2|Bk(3+)}} ions are green in most acids. The color of {{chem2|Bk(4+)}} ions is yellow in [[hydrochloric acid]] and orange-yellow in [[sulfuric acid]].{{sfn|Peterson|Hobart|1984|p=55}}{{sfn|Holleman|Wiberg|2007|p=1956}}{{sfn|Greenwood|Earnshaw|1997|p=1265}} Berkelium does not react rapidly with [[oxygen]] at room temperature, possibly due to the formation of a protective oxide layer surface. However, it reacts with molten metals, [[hydrogen]], [[halogen]]s, [[chalcogen]]s and [[pnictogen]]s to form various binary compounds.{{sfn|Peterson|Hobart|1984|p=45}}

In 2025 an [[Organometallic chemistry|organometallic]] compound containing berkelium was synthesized from 0.3&nbsp;mg of berkelium and named berkelocene.<ref>{{Cite journal |last=Russo |first=Dominic R. |last2=Gaiser |first2=Alyssa N. |last3=Price |first3=Amy N. |last4=Sergentu |first4=Dumitru-Claudiu |last5=Wacker |first5=Jennifer N. |last6=Katzer |first6=Nicholas |last7=Peterson |first7=Appie A. |last8=Branson |first8=Jacob A. |last9=Yu |first9=Xiaojuan |last10=Kelly |first10=Sheridon N. |last11=Ouellette |first11=Erik T. |last12=Arnold |first12=John |last13=Long |first13=Jeffrey R. |last14=Lukens |first14=Wayne W. |last15=Teat |first15=Simon J. |date=2025-02-28 |title=Berkelium–carbon bonding in a tetravalent berkelocene |url=https://www.science.org/doi/10.1126/science.adr3346 |journal=Science |volume=387 |issue=6737 |pages=974–978 |doi=10.1126/science.adr3346}}</ref>