Flerovium

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Flerovium
114Fl
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Pb

Fl

(Uho)
ununtriumfleroviumununpentium
Flerovium in the periodic table
Appearance
unknown
General properties
Name, symbol, number flerovium, Fl, 114
Pronunciation /flɨˈrviəm/
fli-ROH-vee-əm[1]
Element category unknown
but probably a poor metal
Group, period, block 14, 7, p
Standard atomic weight [289]
Electron configuration [Rn] 5f14 6d10 7s2 7p2
(predicted)[2]
2, 8, 18, 32, 32, 18, 4
(predicted)
Physical properties
Phase solid (predicted)[2]
Density (near r.t.) 14 (predicted)[3] g·cm−3
Melting point 340 K, 67 °C, 160 (predicted)[3] °F
Boiling point 420 K, 147 °C, 297 (predicted)[3][4][5] °F
Heat of vaporization 38 (predicted)[3] kJ·mol−1
Atomic properties
Oxidation states 0, 2, 4 (predicted)[2]
Ionization energies
(more)
1st: 823.9 (predicted)[2] kJ·mol−1
2nd: 1601.6 (predicted)[3] kJ·mol−1
3rd: 3367.3 (predicted)[3] kJ·mol−1
Atomic radius 180 (predicted)[2][3] pm
Covalent radius 171–177 (extrapolated)[4] pm
Miscellanea
CAS registry number 54085-16-4
History
Naming after Flerov Laboratory of Nuclear Reactions (itself named after Georgy Flyorov)[6]
Discovery Joint Institute for Nuclear Research and Lawrence Livermore National Laboratory (1999)
Most stable isotopes
Main article: Isotopes of flerovium
iso NA half-life DM DE (MeV) DP
289Fl syn 2.6 s α 9.82,9.48 285Cn
289mFl ? syn 1.1 min α 9.67 285mCn ?
288Fl syn 0.8 s α 9.94 284Cn
287Fl syn 0.48 s α 10.02 283Cn
287mFl ?? syn 5.5 s α 10.29 283mCn ??
286Fl syn 0.13 s 40% α 10.19 282Cn
60% SF
285Fl syn 125 ms α 281Cn
· references

Flerovium is the superheavy artificial chemical element with the symbol Fl and atomic number 114. It is an extremely radioactive element that can only be created in the laboratory and does not occur in nature. The element is named after the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research in Dubna, Russia, where the element was discovered in 1998. The name of the laboratory, in turn, honors the Russian physicist Georgy Flyorov. The name was adopted by IUPAC on May 30, 2012.

In the periodic table of the elements, it is a transactinide element in the p-block. It is a member of the 7th period and is currently placed as the heaviest known member of the carbon group. Initial chemical studies performed in 2007–2008 indicated that flerovium was unexpectedly volatile for a group 14 element;[7] in preliminary results it even seemed to exhibit properties similar to those of the noble gases.[8] More recent results show that flerovium's reaction with gold is similar to that of copernicium, showing that it is a very volatile element that may even be gaseous at standard temperature and pressure, and that while it would show metallic properties, consistent with it being the heavier homologue of lead, it would also be the least reactive metal in group 14.

About 80 atoms of flerovium have been observed to date: 50 were synthesized directly, while the rest were made from the radioactive decay of even heavier elements. All of these flerovium atoms have been shown to have mass numbers from 285 to 289. The most stable known flerovium isotope, flerovium-289, has a half-life of around 2.6 seconds, but it is possible that this flerovium isotope may have a nuclear isomer with a longer half-life of 66 seconds; this would be one of the longest half-lives of any isotope of a superheavy element. Flerovium is predicted to be near the centre of the theorized island of stability, and it is expected that heavier flerovium isotopes, especially the possibly doubly magic flerovium-298, may have even longer half-lives.

History[edit]

Pre-discovery[edit]

From the late 1940s to the early 1960s, the early days of the synthesis of heavier and heavier transuranium elements, it was predicted that since such heavy elements did not occur in nature, they would have shorter and shorter half-lives to spontaneous fission, until they stopped being able to exist altogether at around element 108. Initial work in the synthesis of the actinides appeared to confirm this.[9] However, the nuclear shell model was introduced in the late 1960s, which stated that the protons and neutrons formed shells within a nucleus, just like electrons forming electron shells within an atom. The noble gases are unreactive due to their having full electron shells; thus it was theorized that elements with full nuclear shells – having so-called "magic" numbers of protons or neutrons – would be stabilized against radioactive decay. A doubly-magic isotope, having magic numbers of both protons and neutrons, would be especially stabilized, and it was calculated that the next doubly-magic isotope after lead-208 would be flerovium-298 with 114 protons and 184 neutrons, which would form the centre of a so-called "island of stability".[9] This island of stability, supposedly centering around elements 112 to element 118, would come just after a long "sea of instability" from elements 101 to 111,[9] and the flerovium isotopes in it were speculated in 1966 to have half-lives in excess of a hundred million years.[10] It was not until thirty years later, however, that the first isotopes of flerovium would be synthesized.[9] More recent work, however, suspects that the local islands of stability around hassium and flerovium are due to these nuclei being respectively deformed and oblate, which make them resistant towards spontaneous fission, and that the true island of stability for spherical nuclei occurs at around unbibium-306 (with 122 protons and 184 neutrons).[11]

Discovery[edit]

Flerovium was first synthesized in December 1998 by a team of scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia led by Yuri Oganessian, who bombarded a target of plutonium-244 with accelerated nuclei of calcium-48:

244
94
Pu
+ 48
20
Ca
292
114
Fl
289
114
Fl
+ 3 1
0
n

A single atom of flerovium, decaying by alpha emission with a half-life of 30 seconds, was detected. This observation was assigned to the isotope flerovium-289 and was subsequently published in January 1999.[12] However, the decay chain observed has not been repeated and the exact identity of this activity is unknown, although it is possible that it is due to a metastable isomer, namely 289mFl.[13][14]

Glenn T. Seaborg, a scientist at the Lawrence Berkeley National Laboratory who had been involved in work to synthesize such superheavy elements, stated in December 1997 that "one of his longest-lasting and most cherished dreams was to see one of these magic elements";[9] he received notice of the synthesis of flerovium from his colleague Albert Ghiorso soon after its publication 1999. Ghiorso later recalled:[15]

I wanted Glenn to know, so I went to his bedside and told him. I thought I saw a gleam in his eye, but the next day when I went to visit him he didn't remember seeing me. As a scientist, he had died when he had that stroke.[15]

— Albert Ghiorso

Road to confirmation[edit]

In March 1999, the same team replaced the 244Pu target with a 242Pu one in order to produce other flerovium isotopes. This time two atoms of flerovium were produced, alpha decaying with a half-life of 5.5 s. They were assigned as 287Fl.[16] Once again, this activity has not been seen again and it is unclear what nucleus was produced. It is possible that it was a meta-stable isomer, namely 287mFl.[17]

The now-confirmed discovery of flerovium was made in June 1999 when the Dubna team repeated the first reaction from 1998. This time, two atoms of element 114 were produced; they alpha decayed with a half-life of 2.6 s.[13] This activity was initially assigned to 288Fl in error, due to the confusion regarding the above observations. Further work in December 2002 finally allowed a positive reassignment to 289Fl.[17]

In May 2009, the Joint Working Party (JWP) of IUPAC published a report on the discovery of copernicium in which they acknowledged the discovery of the isotope 283Cn.[18] This therefore implied the de facto discovery of flerovium, from the acknowledgment of the data for the synthesis of 287Fl and 291Lv (see below), relating to 283Cn. The discovery of the isotopes flerovium-286 and -287 was confirmed in January 2009 at Berkeley. This was followed by confirmation of flerovium-288 and -289 in July 2009 at the GSI. In 2011, IUPAC evaluated the Dubna team experiments of 1999–2007. Whereas they found the early data inconclusive, the results of 2004–2007 were accepted as identification of flerovium, and the element was officially recognized as having been discovered.[19]

Stamp of Russia, issued in 2013, dedicated to Georgy Flyorov and flerovium

Naming[edit]

Using Mendeleev's nomenclature for unnamed and undiscovered elements, flerovium is sometimes called eka-lead. In 1979, IUPAC published recommendations according to which the element was to be called ununquadium (with the corresponding symbol of Uuq),[20] a systematic element name as a placeholder, until the discovery of the element is confirmed and a permanent name is decided on. The recommendations were mostly ignored among scientists, who called it "element 114", with the symbol of (114) or even simply 114.[2]

According to IUPAC recommendations, the discoverer(s) of a new element has the right to suggest a name.[21] After the discovery of flerovium and livermorium was recognized by IUPAC on 1 June 2011, IUPAC asked the discovery team at the JINR to suggest permanent names for those two elements. The Dubna team chose to name element 114 flerovium (symbol Fl),[22][23] after the founder of the Russian institute, Flerov Laboratory of Nuclear Reactions, the Soviet physicist Georgy Flyorov (also spelled Flerov).[24] However, IUPAC officially named flerovium after the Flerov Laboratory of Nuclear Reactions (an older name for the JINR), not after Flyorov himself.[6] Flyorov is known for writing to Stalin in April 1942 and pointing out the conspicuous silence in scientific journals within the field of nuclear fission in the United States, Great Britain, and Germany. Flyorov deduced that this research must have become classified information in those countries. Flyorov's work and urgings led to the eventual development of the USSR's own atomic bomb project.[23]

Predicted properties[edit]

Nuclear stability and isotopes[edit]

Chronology of isotope discovery
Isotope Year discovered Discovery reaction
285Fl 2010 242Pu (48Ca, 5n)
286Fl 2002 249Cf (48Ca, 3n)
287aFl 2002 244Pu (48Ca, 5n)
287bFl 1999 242Pu (48Ca, 3n)
288Fl 2002 244Pu (48Ca, 4n)
289aFl 1999 244Pu (48Ca, 3n)
289bFl ? 1998 244Pu (48Ca, 3n)

Retracted isotopes[edit]

285Fl

In the claimed synthesis of 293Uuo in 1999, the isotope 285Fl was identified as decaying by 11.35 MeV alpha emission with a half-life of 0.58 ms. The claim was retracted in 2001 after it was discovered that the data has been fabricated.[25] This isotope was finally created in 2010 and its decay properties did not match the retracted decay data.

Fission of compound nuclei with an atomic number of 114[edit]

Several experiments have been performed between 2000 and 2004 at the Flerov Laboratory of Nuclear Reactions in Dubna studying the fission characteristics of the compound nucleus 292Fl. The nuclear reaction used is 244
94
Pu
 + 48
20
Ca
. The results have revealed how nuclei such as this fission predominantly by expelling closed shell nuclei such as 132Sn (Z = 50, N = 82). It was also found that the yield for the fusion-fission pathway was similar between 48Ca and 58Fe projectiles, indicating a possible future use of 58Fe projectiles in superheavy element formation.[26]

Nuclear isomerism[edit]

289Fl

In the first claimed synthesis of flerovium, an isotope assigned as 289Fl decayed by emitting a 9.71 MeV alpha particle with a lifetime of 30 seconds. This activity was not observed in repetitions of the direct synthesis of this isotope. However, in a single case from the synthesis of 293Lv, a decay chain was measured starting with the emission of a 9.63 MeV alpha particle with a lifetime of 2.7 minutes. All subsequent decays were very similar to that observed from 289Fl, presuming that the parent decay was missed. This strongly suggests that the activity should be assigned to an isomeric level. The absence of the activity in recent experiments indicates that the yield of the isomer is ~20% compared to the supposed ground state and that the observation in the first experiment was a fortunate (or not as the case history indicates). Further research is required to resolve these issues.

287Fl

In a manner similar to those for 289Fl, first experiments with a 242Pu target identified an isotope 287Fl decaying by emission of a 10.29 MeV alpha particle with a lifetime of 5.5 seconds. The daughter spontaneously fissioned with a lifetime in accord with the previous synthesis of 283Cn. Both these activities have not been observed since (see copernicium). However, the correlation suggests that the results are not random and are possible due to the formation of isomers whose yield is obviously dependent on production methods. Further research is required to unravel these discrepancies.

Decay characteristics[edit]

Theoretical estimation of the alpha decay half-lives of the isotopes of the flerovium supports the experimental data.[27][28] The fission-survived isotope 298Fl is predicted to have alpha decay half-life around 17 days.[29][30]

In search for the island of stability: 298Fl[edit]

According to macroscopic-microscopic (MM) theory,[31] Z = 114 is the next spherical magic number. This means that such nuclei are spherical in their ground state and should have high, wide fission barriers to deformation and hence long SF partial half-lives.

In the region of Z = 114, MM theory indicates that N = 184 is the next spherical neutron magic number and puts forward the nucleus 298Fl as a strong candidate for the next spherical doubly magic nucleus, after 208Pb (Z = 82, N = 126). 298Fl is taken to be at the centre of a hypothetical "island of stability". However, other calculations using relativistic mean field (RMF) theory propose Z = 120, 122, and 126 as alternative proton magic numbers depending upon the chosen set of parameters. It is possible that rather than a peak at a specific proton shell, there exists a plateau of proton shell effects from Z = 114–126.

It should be noted that calculations suggest that the minimum of the shell-correction energy and hence the highest fission barrier exists for 297Uup, caused by pairing effects. Due to the expected high fission barriers, any nucleus within this island of stability exclusively decays by alpha-particle emission and, as such, the nucleus with the longest half-life is predicted to be 298Fl. The expected half-life is unlikely to reach values higher than about 10 minutes, unless the N = 184 neutron shell proves to be more stabilising than predicted, for which there exists some evidence.[citation needed] In addition, 297Fl may have an even-longer half-life due to the effect of the odd neutron, creating transitions between similar Nilsson levels with lower Qα values.

In either case, an island of stability does not represent nuclei with the longest half-lives, but those that are significantly stabilized against fission by closed-shell effects.

Evidence for Z = 114 closed proton shell[edit]

While evidence for closed neutron shells can be deemed directly from the systematic variation of Qα values for ground-state to ground-state transitions, evidence for closed proton shells comes from (partial) spontaneous fission half-lives. Such data can sometimes be difficult to extract due to low production rates and weak SF branching. In the case of Z = 114, evidence for the effect of this proposed closed shell comes from the comparison between the nuclei pairings 282Cn (TSF1/2 = 0.8 ms) and 286Fl (TSF1/2 = 130 ms), and 284Cn (TSF = 97 ms) and 288Fl (TSF > 800 ms). Further evidence would come from the measurement of partial SF half-lives of nuclei with Z > 114, such as 290Lv and 292Uuo (both N = 174 isotones). The extraction of Z = 114 effects is complicated by the presence of a dominating N = 184 effect in this region.

Difficulty of synthesis of 298Fl[edit]

The direct synthesis of the nucleus 298Fl by a fusion–evaporation pathway is impossible since no known combination of target and projectile can provide 184 neutrons in the compound nucleus.

It has been suggested that such a neutron-rich isotope can be formed by the quasifission (partial fusion followed by fission) of a massive nucleus. Such nuclei tend to fission with the formation of isotopes close to the closed shells Z = 20 / N = 20 (40Ca), Z =50 / N = 82 (132Sn) or Z = 82 / N = 126 (208Pb/209Bi). If Z = 114 does represent a closed shell, then the hypothetical reaction below may represent a method of synthesis:

204
80
Hg
+ 136
54
Xe
298
114
Fl
+ 40
20
Ca
+ 2 1
0
n

Recently it has been shown that the multi-nucleon transfer reactions in collisions of actinide nuclei (such as uranium and curium) might be used to synthesize the neutron rich superheavy nuclei located at the island of stability.[32]

It is also possible that 298Fl can be synthesized by the alpha decay of a massive nucleus. Such a method would depend highly on the SF stability of such nuclei, since the alpha half-lives are expected to be very short. The yields for such reactions will also most likely be extremely small. One such reaction is:

244
94
Pu
(96
40
Zr
,2n) → 338
134
Utq
298
114
Fl
+ 10 4
2
He

Atomic and physical[edit]

Flerovium is a member of group 14 in the periodic table, below carbon, silicon, germanium, tin, and lead. Every previous group 14 element has four electrons in its valence shell, forming a valence electron configuration of ns2np2. In flerovium's case, the trend will be continued and the valence electron configuration is predicted to be 7s27p2;[2] therefore, flerovium will behave similarly to its lighter congeners in many respects. However, notable differences are likely to arise; a largely contributing effect is the spin–orbit (SO) interaction—the mutual interaction between the electrons' motion and spin. It is especially strong for the superheavy elements, because their electrons move much faster than in lighter atoms, at velocities comparable to the speed of light, which is where the differences arise.[33] In relation to flerovium atoms, it lowers the 7s and the 7p electron energy levels (stabilizing the corresponding electrons), but two of the 7p electron energy levels are stabilized more than the other four.[34] The stabilization of the 7s electrons is called the inert pair effect, and the effect "tearing" the 7p subshell into the more stabilized and the less stabilized parts is called subshell splitting. Computation chemists see the split as a change of the second (azimuthal) quantum number l from 1 to 1/2 and 3/2 for the more stabilized and less stabilized parts of the 7p subshell, respectively.[35][a] For many theoretical purposes, the valence electron configuration may be represented to reflect the 7p subshell split as 7s2
7p2
1/2
.[2] These effects cause flerovium's chemistry to be somewhat different from that of its lighter neighbours.

Due to the spin-orbit splitting of the 7p subshell being very large in flerovium, and the fact that both flerovium's filled orbitals in the seventh shell are stabilized relativistically, the valence electron configuration of flerovium may be considered to have a completely filled shell, making flerovium a very noble metal. Consistent with this, its first ionization energy of 8.539 eV should be the highest in group 14.[2] This closed-shell electron configuration results in the metallic bonding in metallic flerovium being much weaker than in the preceding and following elements; thus, flerovium is expected to have a low boiling point,[2] and has recently been suggested to be possibly a gaseous metal.[11] Earlier predictions stated the melting and boiling points of flerovium to be around 70 °C and 150 °C,[2] significantly lower than the values for the lighter group 14 elements (those of lead are 327 °C and 1749 °C respectively), and continuing the trend of decreasing boiling points down the group. In the solid state, flerovium is expected to be a dense metal, with a density variously predicted to be either 22 g·cm−3 or 14 g·cm−3.[2] The electron of the hydrogen-like flerovium atom (oxidized so that it only has one electron, Fl113+) is expected to move so fast that it has a mass 1.79 times that of a stationary electron, due to relativistic effects. For comparison, the figures for hydrogen-like lead and tin are expected to be 1.25 and 1.073 respectively.[36] Flerovium would form weaker metal–metal bonds than lead and would be adsorbed less on surfaces.[36]

Chemical[edit]

Flerovium is projected to be the second member of the 7p series of chemical elements and the heaviest known member of group 14 in the periodic table, below lead. The first five members of this group show the group oxidation state of +4 and the latter members have an increasingly prominent +2 chemistry due to the onset of the inert pair effect. Tin represents the point at which the stability of the +2 and +4 states are similar, and lead(II) is the most stable of all the chemically well-understood group 14 elements in the +2 oxidation state.[2] The 7s orbitals are very highly stabilized in flerovium and thus a very large sp3 orbital hybridization is required to achieve the +4 oxidation state; thus flerovium is expected to be even more stable than lead in its strongly predominant +2 oxidation state and its +4 oxidation state should be highly unstable.[2] For example, flerovium dioxide (FlO2) is expected to be highly unstable to decomposition into its constituent elements (and indeed would not be formed from the direct reaction of flerovium with oxygen),[2][37] while flerovane (FlH4) is predicted to be much more thermodynamically unstable than plumbane, spontaneously decomposing into flerovium(II) hydride (FlH2) and hydrogen gas.[38] The only stable flerovium(IV) compound is expected to be the fluoride, FlF4,[39] and even this may be due to sd hybridizations rather than sp3 hybridization.[40] The corresponding polyfluoride anion FlF2−
6
should be unstable to hydrolysis in aqueous solution, and flerovium(II) polyhalide anions such as FlBr
3
and FlI
3
are predicted to form preferentially in flerovium-containing solutions.[2] Due to the relativistic stabilization of flerovium's 7s27p2
1/2
valence electron configuration, the 0 oxidation state should also be more stable for flerovium than for lead, as the 7p1/2 electrons begin to also exhibit a mild inert pair effect:[2] this stabilization of the neutral state may bring about some similarities between the behaviour of flerovium and the noble gas radon.[8] Flerovium(IV) should be even more electronegative than lead(IV);[39] lead(IV) has electronegativity 2.33 on the Pauling scale, while the lead(II) value is only 1.87.

Flerovium(II) should be much more stable than lead(II), and polyhalide ions and compounds of types FlX+, FlX2, FlX
3
, and FlX2−
4
(X = Cl, Br, I) are expected to form readily. Fluorine would be able to also form the unstable flerovium(IV) analogues.[2] All the flerovium dihalides are expected to be stable,[2] with the difluoride being water-soluble,[41] while spin-orbit effects would destabilize flerovium dihydride (FlH2) by almost 2.6 eV.[37] In solution, flerovium would also form the oxoanion flerovite (FlO2−
2
) in aqueous solution, analogous to plumbite. Flerovium(II) sulfate (FlSO4) and sulfide (FlS) should be very insoluble in water, while flerovium(II) acetate (FlC2H3O2) and nitrate (Fl(NO3)2) should be quite water-soluble.[3] The standard electrode potential for the reduction of Fl2+ ions to metallic flerovium is estimated to be around +0.9 eV, confirming the increased stability of flerovium in the neutral state.[2] In general, due to the relativistic stabilization of the 7p1/2 spinor, Fl2+ is expected to have properties intermediate between those of Hg2+ or Cd2+ and its actual lighter congener Pb2+.[2]

Experimental chemistry[edit]

Two experiments were performed in April–May 2007 in a joint FLNR-PSI collaboration aiming to study the chemistry of copernicium. The first experiment involved the reaction 242Pu(48Ca,3n)287Fl and the second the reaction 244Pu(48Ca,4n)288Fl.[42] The adsorption properties of the resultant atoms on a gold surface were compared with those of the noble gas radon, as it was then expected that copernicium's full-shell electron configuration would lead to noble-gas like behaviour.[42] Noble gases interact with metal surfaces very weakly, which is uncharacteristic of metals.[42]

The first experiment allowed detection of three atoms of 283Cn but also seemingly detected 1 atom of 287Fl. This result was a surprise given the transport time of the product atoms is ~2 s, so flerovium atoms should decay before adsorption. In the second reaction, 2 atoms of 288Fl and possibly 1 atom of 289Fl were detected. Two of the three atoms portrayed adsorption characteristics associated with a volatile, noble-gas-like element, which has been suggested but is not predicted by more recent calculations. These experiments did however provide independent confirmation for the discovery of copernicium, flerovium, and livermorium via comparison with published decay data. Further experiments in 2008 to confirm this important result detected a single atom of 289Fl, which provided data that agreed with previous data that supported flerovium having a noble-gas-like interaction with gold.[42]

The experimental support for a noble-gas-like flerovium was soon to weaken abruptly, however. In 2009 and 2010, the FLNR-PSI collaboration synthesized further atoms of flerovium to follow up their 2007 and 2008 studies. In particular, the first three flerovium atoms synthesized in the 2010 study suggested again a noble-gas-like character, but the complete set taken together resulted in a more ambiguous interpretation.[43] In their paper, the scientists refrained from calling flerovium's chemical properties "close to those of noble gases", as had previously been done in the 2008 study.[43] Flerovium's volatility was again measured through interactions with a gold surface, and provided indications that the volatility of flerovium was comparable to that of mercury, astatine, and the simultaneously investigated copernicium, which had been shown in the study to be a very volatile noble metal, conforming to its being the heaviest group 12 element known.[43] Nevertheless, it was pointed out that this volatile behaviour was not expected for a usual group 14 metal.[43]

In even later experiments from 2012, the chemical properties of flerovium were revealed to be more and more metallic than noble-gas-like. Jens Volker Kratz and Christoph Düllmann specifically named copernicium and flerovium as belonging to a new category of "volatile metals"; Kratz even speculated that they might be gaseous at standard temperature and pressure.[11][44] These "volatile metals", as a category, were expected to fall somewhat in between normal metals and noble gases in terms of absorption properties.[11] Contrary to the 2009 and 2010 results, it was shown in the 2012 experiments that the interactions of flerovium and copernicium respectively with gold were about equal.[45] Further studies in fact showed that flerovium was in reality more reactive than copernicium, in exact contradiction to previous experiments and predictions.[11]

See also[edit]

Notes[edit]

  1. ^ The quantum number corresponds to the letter in the electron orbital name: 0 to s, 1 to p, 2 to d, etc. See azimuthal quantum number for more information.

References[edit]

  1. ^ "Flerovium and Livermorium". Periodic Table of Videos. The University of Nottingham. Retrieved 4 June 2012. 
  2. ^ a b c d e f g h i j k l m n o p q r s t u Haire, R. G. (2006). "Transactinides and the future elements". In Morss, L. R.; Edelstein, N. M.; Fuger, J. The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Springer. ISBN 978-1-4020-3555-5. 
  3. ^ a b c d e f g h Fricke, Burkhard (1975). "Superheavy elements: a prediction of their chemical and physical properties". Recent Impact of Physics on Inorganic Chemistry 21: 89–144. doi:10.1007/BFb0116498. Retrieved 4 October 2013. 
  4. ^ a b Bonchev, D.; Kamenska, V. (1981). "Predicting the Properties of the 113–120 Transactinide Elements". Journal of Physical Chemistry 85 (9): 1177–1186. doi:10.1021/j150609a021. 
  5. ^ Seaborg, G. T. "Transuranium element". Encyclopædia Britannica. Retrieved 2010-03-16. 
  6. ^ a b "Element 114 is Named Flerovium and Element 116 is Named Livermorium" (Press release). IUPAC. 30 May 2012. 
  7. ^ Eichler, R.; et al. (2010). "Indication for a volatile element 114". Radiochimica Acta 98 (3): 133–139. doi:10.1524/ract.2010.1705. 
  8. ^ a b Gäggeler, H. W. (5–7 November 2007). "Gas Phase Chemistry of Superheavy Elements". Paul Scherrer Institute. Archived from the original on 22 February 2012. Retrieved 10 August 2013. 
  9. ^ a b c d e Sacks, O. (8 February 2004). "Greetings From the Island of Stability". The New York Times. 
  10. ^ Emsley, John (2011). Nature's Building Blocks: An A-Z Guide to the Elements (New ed.). New York, NY: Oxford University Press. p. 580. ISBN 978-0-19-960563-7. 
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  12. ^ Oganessian, Yu. Ts.; et al. (1999). "Synthesis of Superheavy Nuclei in the 48Ca + 244Pu Reaction". Physical Review Letters 83 (16): 3154. Bibcode:1999PhRvL..83.3154O. doi:10.1103/PhysRevLett.83.3154. 
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  14. ^ Oganessian, Yu. Ts.; et al. (2004). "Measurements of cross sections and decay properties of the isotopes of elements 112, 114, and 116 produced in the fusion reactions 233,238U, 242Pu, and 248Cm + 48Ca". Physical Review C 70 (6): 064609. Bibcode:2004PhRvC..70f4609O. doi:10.1103/PhysRevC.70.064609. 
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  18. ^ Barber, R. C.; Gäggeler, H. W.; Karol, P. J.; Nakahara, H.; Vardaci, E.; Vogt, E. (2009). "Discovery of the element with atomic number 112 (IUPAC Technical Report)". Pure and Applied Chemistry 81 (7): 1331. doi:10.1351/PAC-REP-08-03-05. 
  19. ^ Barber, R. C.; Karol, P. J.; Nakahara, H.; Vardaci, E.; Vogt, E. W. (2011). "Discovery of the elements with atomic numbers greater than or equal to 113 (IUPAC Technical Report)". Pure and Applied Chemistry 83 (7): 1485. doi:10.1351/PAC-REP-10-05-01. 
  20. ^ Chatt, J. (1979). "Recommendations for the naming of elements of atomic numbers greater than 100". Pure and Applied Chemistry 51 (2): 381–384. doi:10.1351/pac197951020381. 
  21. ^ Koppenol, W. H. (2002). "Naming of new elements (IUPAC Recommendations 2002)". Pure and Applied Chemistry 74 (5): 787. doi:10.1351/pac200274050787. 
  22. ^ Brown, M. (6 June 2011). "Two Ultraheavy Elements Added to Periodic Table". Wired. Retrieved 7 June 2011. 
  23. ^ a b Welsh, J. (2 December 2011). "Two Elements Named: Livermorium and Flerovium". LiveScience. Retrieved 2 December 2011. 
  24. ^ "Российские физики предложат назвать 116 химический элемент московием" [Russian physicists have offered to call 116 chemical element moscovium]. RIA Novosti. 26 March 2011. Retrieved 8 May 2011.  Mikhail Itkis, the vice-director of JINR stated: "We would like to name element 114 after Georgy Flerov – flerovium, and the second [element 116] – moscovium, not after Moscow, but after Moscow Oblast".
  25. ^ Johnson, G. (15 October 2002). "At Lawrence Berkeley, Physicists Say a Colleague Took Them for a Ride". The New York Times. Archived from the original on 2013-05-30. 
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  30. ^ Roy Chowdhury, P.; Samanta, C.; Basu, D. N. (2008). "Nuclear half-lives for α-radioactivity of elements with 100 ≤ Z ≤ 130". Atomic Data and Nuclear Data Tables 94 (6): 781–806. arXiv:0802.4161. Bibcode:2008ADNDT..94..781C. doi:10.1016/j.adt.2008.01.003. 
  31. ^ Krane, K. S. (1987). Introductory Nuclear Physics. John Wiley & Sons. pp. 121–123, 433. ISBN 978-0-471-80553-3. 
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  36. ^ a b Thayer 2010, pp. 64.
  37. ^ a b Pershina 2010, p. 502.
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  43. ^ a b c d Eichler, R.; Aksenov, N. V.; Albin, Yu. V.; Belozerov, A. V.; Bozhikov, G. A.; Chepigin, V. I.; Dmitriev, S. N.; Dressler, R.; Gäggeler, H. W.; Gorshkov, V. A.; Henderson, G. S. (2010). "Indication for a volatile element 114". Radiochimica Acta 98 (3): 133–139. doi:10.1524/ract.2010.1705. 
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  45. ^ Düllmann, Christoph E. (18 September 2012). "Superheavy element 114 is a volatile metal". 

Bibliography[edit]

  • Thayer, J. S. (2010). Chemistry of heavier main group elements. p. 63. 
  • Stysziński, J. (2010). Why do we need relativistic computational methods?. p. 99. 
  • Pershina, V. (2010). Electronic structure and chemistry of the heaviest elements. p. 450. 

External links[edit]