Editing Rutherfordium (section)

==Predicted properties==
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Very few properties of rutherfordium or its compounds have been measured; this is due to its extremely limited and expensive production<ref name="Bloomberg">{{Cite web|url=https://www.bloomberg.com/news/features/2019-08-28/making-new-elements-doesn-t-pay-just-ask-this-berkeley-scientist|title=Making New Elements Doesn't Pay. Just Ask This Berkeley Scientist|last=Subramanian|first=S.|website=[[Bloomberg Businessweek]]|access-date=2020-01-18|archive-date=2020-11-14|archive-url=https://archive.today/20201114183428/https://www.bloomberg.com/news/features/2019-08-28/making-new-elements-doesn-t-pay-just-ask-this-berkeley-scientist|url-status=live}}</ref> and the fact that rutherfordium (and its parents) decays very quickly. A few singular chemistry-related properties have been measured, but properties of rutherfordium metal remain unknown and only predictions are available.

===Chemical===
Rutherfordium is the first [[transactinide element]] and the second member of the 6d series of transition metals. Calculations on its [[ionization potential]]s, [[atomic radius]], as well as radii, orbital energies, and ground levels of its ionized states are similar to that of [[hafnium]] and very different from that of [[lead]]. Therefore, it was concluded that rutherfordium's basic properties will resemble those of other [[group 4 element]]s, below [[titanium]], [[zirconium]], and hafnium.<ref name="Rf263">{{cite journal |url=http://www.ulrich-rieth.de/publikationen/RCA0301_059.PDF |title=An EC-branch in the decay of 27-s<sup>263</sup>Db: Evidence for the new isotope <sup>263</sup>Rf |author=Kratz, J. V. |journal=Radiochim. Acta |volume=91 |issue=1–2003 |pages=59–62 |date=2003 |doi=10.1524/ract.91.1.59.19010 |last2=Nähler |first2=A. |last3=Rieth |first3=U. |last4=Kronenberg |first4=A. |last5=Kuczewski |first5=B. |last6=Strub |first6=E. |last7=Brüchle |first7=W. |last8=Schädel |first8=M. |last9=Schausten |first9=B. |last10=Türler |first10=A. |last11=Gäggeler |first11=H. W. |last12=Jost |first12=D. T. |last13=Gregorich |first13=K. E. |last14=Nitsche |first14=H. |last15=Laue |first15=C. |last16=Sudowe |first16=R. |last17=Wilk |first17=P. A. |s2cid=96560109 |display-authors=8 |archive-url=https://web.archive.org/web/20090225154858/http://www.ulrich-rieth.de/publikationen/RCA0301_059.PDF |archive-date=2009-02-25 }}</ref><ref name="Kratz03" /> Some of its properties were determined by gas-phase experiments and aqueous chemistry. The oxidation state +4 is the only stable state for the latter two elements and therefore rutherfordium should also exhibit a stable +4 state.<ref name="Kratz03" /> In addition, rutherfordium is also expected to be able to form a less stable +3 state.<ref name="Haire" /> The [[standard reduction potential]] of the Rf<sup>4+</sup>/Rf couple is predicted to be higher than −1.7&nbsp;V.{{Fricke1975}}

Initial predictions of the chemical properties of rutherfordium were based on calculations which indicated that the relativistic effects on the electron shell might be strong enough that the [[p orbital|7p orbitals]] would have a lower energy level than the [[d orbital|6d orbitals]], giving it a [[valence electron]] configuration of 6d<sup>1</sup> 7s<sup>2</sup> 7p<sup>1</sup> or even 7s<sup>2</sup> 7p<sup>2</sup>, therefore making the element behave more like [[lead]] than hafnium. With better calculation methods and experimental studies of the chemical properties of rutherfordium compounds it could be shown that this does not happen and that rutherfordium instead behaves like the rest of the [[group 4 element]]s.<ref name="Haire" /><ref name="Kratz03">{{cite journal|doi=10.1351/pac200375010103 |url=http://stage.iupac.org/originalWeb/publications/pac/2003/pdf/7501x0103.pdf |title=Critical evaluation of the chemical properties of the transactinide elements (IUPAC Technical Report) |date=2003 |last1=Kratz |first1=J. V. |journal=Pure and Applied Chemistry |volume=75 |issue=1 |page=103 |s2cid=5172663 |archive-url=https://web.archive.org/web/20110726195721/http://stage.iupac.org/originalWeb/publications/pac/2003/pdf/7501x0103.pdf |archive-date=2011-07-26}}</ref> Later it was shown in ab initio calculations with the high level of accuracy<ref name="Eliav1995">{{cite journal |last1=Eliav |first1=E. |last2=Kaldor |first2=U. |last3=Ishikawa |first3=Y. |title=Ground State Electron Configuration of Rutherfordium: Role of Dynamic Correlation |journal=Physical Review Letters |volume=74 |issue=7 |pages=1079–1082 |year=1995 |doi=10.1103/PhysRevLett.74.1079 |pmid=10058929 |bibcode=1995PhRvL..74.1079E}}</ref><ref name="Mosyagin2010">{{cite journal |last1=Mosyagin |first1=N. S. |last2=Tupitsyn |first2=I. I. |last3=Titov |first3=A. V. |title=Precision Calculation of the Low-Lying Excited States of the Rf Atom |journal=Radiochemistry |volume=52 |issue=4 |pages=394–398 |year=2010 |doi=10.1134/S1066362210040120 |bibcode=2010Radch..52..394M |s2cid=120721050 }}</ref><ref name="Dzuba2014">{{cite journal |last1=Dzuba |first1=V. A. |last2=Safronova |first2=M. S. |last3=Safronova |first3=U. I. |title=Atomic properties of superheavy elements No, Lr, and Rf |journal=Physical Review A |volume=90 |issue=1 |page=012504 |year=2014 |doi=10.1103/PhysRevA.90.012504 |arxiv=1406.0262 |bibcode=2014PhRvA..90a2504D |s2cid=74871880}}</ref> that the Rf atom has the ground state with the 6d<sup>2</sup> 7s<sup>2</sup> valence configuration and the low-lying excited 6d<sup>1</sup> 7s<sup>2</sup> 7p<sup>1</sup> state with the excitation energy of only 0.3–0.5 eV.

In an analogous manner to zirconium and hafnium, rutherfordium is projected to form a very stable, [[refractory]] oxide, RfO<sub>2</sub>. It reacts with halogens to form tetrahalides, RfX<sub>4</sub>, which hydrolyze on contact with water to form oxyhalides RfOX<sub>2</sub>. The tetrahalides are volatile solids existing as monomeric tetrahedral molecules in the vapor phase.<ref name="Kratz03" />

In the aqueous phase, the Rf<sup>4+</sup> ion hydrolyzes less than titanium(IV) and to a similar extent as zirconium and hafnium, thus resulting in the RfO<sup>2+</sup> ion. Treatment of the halides with halide ions promotes the formation of complex ions. The use of chloride and bromide ions produces the hexahalide complexes {{chem|RfCl|6|2-}} and {{chem|RfBr|6|2-}}. For the fluoride complexes, zirconium and hafnium tend to form hepta- and octa- complexes. Thus, for the larger rutherfordium ion, the complexes {{chem|RfF|6|2-}}, {{chem|RfF|7|3-}} and {{chem|RfF|8|4-}} are possible.<ref name="Kratz03" />

===Physical and atomic===
<section begin=properties />
Rutherfordium is expected to be a solid under normal conditions and have a [[hexagonal close-packed]] crystal structure (<sup>''c''</sup>/<sub>''a''</sub>&nbsp;=&nbsp;1.61), similar to its lighter [[congener (chemistry)|congener]] hafnium.<ref name="hcp" /> It should be a metal with [[density]] ~17&nbsp;g/cm<sup>3</sup>.<ref name=density>{{cite journal |last1=Gyanchandani |first1=Jyoti |last2=Sikka |first2=S. K. |title=Physical properties of the 6 d -series elements from density functional theory: Close similarity to lighter transition metals |journal=Physical Review B |date=10 May 2011 |volume=83 |issue=17 |page=172101 |doi=10.1103/PhysRevB.83.172101 |bibcode=2011PhRvB..83q2101G }}</ref><ref name=kratz>{{cite book |last1=Kratz |last2=Lieser |title=Nuclear and Radiochemistry: Fundamentals and Applications |date=2013 |page=631 |edition=3rd}}</ref> The atomic radius of rutherfordium is expected to be ~150&nbsp;[[picometer|pm]]. Due to relativistic stabilization of the 7s orbital and destabilization of the 6d orbital, Rf<sup>+</sup> and Rf<sup>2+</sup> ions are predicted to give up 6d electrons instead of 7s electrons, which is the opposite of the behavior of its lighter homologs.<ref name="Haire" /> When under high pressure (variously calculated as 72 or ~50 [[gigapascal|GPa]]), rutherfordium is expected to transition to [[body-centered cubic]] crystal structure; hafnium transforms to this structure at 71±1&nbsp;GPa, but has an intermediate ω structure that it transforms to at 38±8&nbsp;GPa that should be lacking for rutherfordium.<ref>{{cite journal | last1=Gyanchandani | first1=Jyoti | last2=Sikka | first2=S.K. | title=Structural properties of rutherfordium: An ab-initio study | journal=Physics Letters A | volume=376 | issue=4 | date=2012 | doi=10.1016/j.physleta.2011.11.053 | pages=620–625 |arxiv=1106.3146| bibcode=2012PhLA..376..620G }}</ref><section end=properties />