Jump to content

Meitnerium

Edit links
This is a good article. Click here for more information.
From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by R8R (talk | contribs) at 11:50, 26 June 2020 (→Introduction: upd). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Meitnerium, 109Mt
Meitnerium
Pronunciation
Mass number[278] (data not decisive)[a]
Meitnerium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Ir
↑
Mt
↓
—
hassium ← meitnerium → darmstadtium
Atomic number (Z)109
Groupgroup 9
Periodperiod 7
Block  d-block
Electron configuration[Rn] 5f14 6d7 7s2 (predicted)[6][7]
Electrons per shell2, 8, 18, 32, 32, 15, 2 (predicted)
Physical properties
Phase at STPsolid (predicted)[8]
Density (near r.t.)27–28 g/cm3 (predicted)[9][10]
Atomic properties
Oxidation statescommon: (none)
(+1), (+3), (+6)[6]
Ionization energies
  • 1st: 800 kJ/mol
  • 2nd: 1820 kJ/mol
  • 3rd: 2900 kJ/mol
  • (more) (all estimated)[6]
Atomic radiusempirical: 128 pm (predicted)[6][11]
Covalent radius129 pm (estimated)[12]
Other properties
Natural occurrencesynthetic
Crystal structure ​face-centered cubic (fcc)
Face-centered cubic crystal structure for meitnerium

(predicted)[8]
Magnetic orderingparamagnetic (predicted)[13]
CAS Number54038-01-6
History
Namingafter Lise Meitner
DiscoveryGesellschaft für Schwerionenforschung (1982)
Isotopes of meitnerium
Main isotopes[3] Decay
abun­dance half-life (t1/2) mode pro­duct
274Mt synth 0.64 s α 270Bh
276Mt synth 0.62 s α 272Bh
278Mt synth 4 s α 274Bh
282Mt synth 67 s?[5] α 278Bh
 Category: Meitnerium
| references

Meitnerium is a synthetic chemical element with the symbol Mt and atomic number 109. It is an extremely radioactive synthetic element (an element not found in nature, but can be created in a laboratory). The most stable known isotope, meitnerium-278, has a half-life of 4.5 seconds, although the unconfirmed meitnerium-282 may have a longer half-life of 67 seconds. The GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany, first created this element in 1982. It is named after Lise Meitner.

In the periodic table, meitnerium is a d-block transactinide element. It is a member of the 7th period and is placed in the group 9 elements, although no chemical experiments have yet been carried out to confirm that it behaves as the heavier homologue to iridium in group 9 as the seventh member of the 6d series of transition metals. Meitnerium is calculated to have similar properties to its lighter homologues, cobalt, rhodium, and iridium.

Introduction

This section is transcluded from Introduction to the heaviest elements. (edit | history)
"Transactinide element" redirects here. Not to be confused with Transuranium element.
Superheavy elements
in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Z ≥ 104 (Rf)

Superheavy elements, also known as transactinide elements, transactinides, or super-heavy elements, or superheavies for short, are the chemical elements with atomic number greater than 104.[14] The superheavy elements are those beyond the actinides in the periodic table; the last actinide is lawrencium (atomic number 103). By definition, superheavy elements are also transuranium elements, i.e., having atomic numbers greater than that of uranium (92). Depending on the definition of group 3 adopted by authors, lawrencium may also be included to complete the 6d series.[15][16][17][18]

Glenn T. Seaborg first proposed the actinide concept, which led to the acceptance of the actinide series. He also proposed a transactinide series ranging from element 104 to 121 and a superactinide series approximately spanning elements 122 to 153 (though more recent work suggests the end of the superactinide series to occur at element 157 instead). The transactinide seaborgium was named in his honor.[19][20]

Superheavies are radioactive and have only been obtained synthetically in laboratories. No macroscopic sample of any of these elements has ever been produced. Superheavies are all named after physicists and chemists or important locations involved in the synthesis of the elements.

IUPAC defines an element to exist if its lifetime is longer than 10−14 seconds, which is the time it takes for the atom to form an electron cloud.[21]

The known superheavies form part of the 6d and 7p series in the periodic table. Except for rutherfordium and dubnium (and lawrencium if it is included), even the longest-lived known isotopes of superheavies have half-lives of minutes or less. The element naming controversy involved elements 102–109. Some of these elements thus used systematic names for many years after their discovery was confirmed. (Usually the systematic names are replaced with permanent names proposed by the discoverers relatively soon after a discovery has been confirmed.)

Introduction

Synthesis of superheavy nuclei

See also: Nucleosynthesis and Nuclear reaction
A graphic depiction of a nuclear fusion reaction
A graphic depiction of a nuclear fusion reaction. Two nuclei fuse into one, emitting a neutron. Reactions that created new elements to this moment were similar, with the only possible difference that several singular neutrons sometimes were released, or none at all.

A superheavy[b] atomic nucleus is created in a nuclear reaction that combines two other nuclei of unequal size[c] into one; roughly, the more unequal the two nuclei in terms of mass, the greater the possibility that the two react.[27] The material made of the heavier nuclei is made into a target, which is then bombarded by the beam of lighter nuclei. Two nuclei can only fuse into one if they approach each other closely enough; normally, nuclei (all positively charged) repel each other due to electrostatic repulsion. The strong interaction can overcome this repulsion but only within a very short distance from a nucleus; beam nuclei are thus greatly accelerated in order to make such repulsion insignificant compared to the velocity of the beam nucleus.[28] The energy applied to the beam nuclei to accelerate them can cause them to reach speeds as high as one-tenth of the speed of light. However, if too much energy is applied, the beam nucleus can fall apart.[28]

Coming close enough alone is not enough for two nuclei to fuse: when two nuclei approach each other, they usually remain together for about 10−20 seconds and then part ways (not necessarily in the same composition as before the reaction) rather than form a single nucleus.[28][29] This happens because during the attempted formation of a single nucleus, electrostatic repulsion tears apart the nucleus that is being formed.[28] Each pair of a target and a beam is characterized by its cross section—the probability that fusion will occur if two nuclei approach one another expressed in terms of the transverse area that the incident particle must hit in order for the fusion to occur.[d] This fusion may occur as a result of the quantum effect in which nuclei can tunnel through electrostatic repulsion. If the two nuclei can stay close past that phase, multiple nuclear interactions result in redistribution of energy and an energy equilibrium.[28]

External videos
video icon Visualization of unsuccessful nuclear fusion, based on calculations from the Australian National University[31]

The resulting merger is an excited state[32]—termed a compound nucleus—and thus it is very unstable.[28] To reach a more stable state, the temporary merger may fission without formation of a more stable nucleus.[33] Alternatively, the compound nucleus may eject a few neutrons, which would carry away the excitation energy; if the latter is not sufficient for a neutron expulsion, the merger would produce a gamma ray. This happens in about 10−16 seconds after the initial nuclear collision and results in creation of a more stable nucleus.[33] The definition by the IUPAC/IUPAP Joint Working Party (JWP) states that a chemical element can only be recognized as discovered if a nucleus of it has not decayed within 10−14 seconds. This value was chosen as an estimate of how long it takes a nucleus to acquire electrons and thus display its chemical properties.[34][e]

Decay and detection

See also: Gaseous ionization detector

The beam passes through the target and reaches the next chamber, the separator; if a new nucleus is produced, it is carried with this beam.[36] In the separator, the newly produced nucleus is separated from other nuclides (that of the original beam and any other reaction products)[f] and transferred to a surface-barrier detector, which stops the nucleus. The exact location of the upcoming impact on the detector is marked; also marked are its energy and the time of the arrival.[36] The transfer takes about 10−6 seconds; in order to be detected, the nucleus must survive this long.[39] The nucleus is recorded again once its decay is registered, and the location, the energy, and the time of the decay are measured.[36]

Stability of a nucleus is provided by the strong interaction. However, its range is very short; as nuclei become larger, its influence on the outermost nucleons (protons and neutrons) weakens. At the same time, the nucleus is torn apart by electrostatic repulsion between protons, and its range is not limited.[40] Total binding energy provided by the strong interaction increases linearly with the number of nucleons, whereas electrostatic repulsion increases with the square of the atomic number, i.e. the latter grows faster and becomes increasingly important for heavy and superheavy nuclei.[41][42] Superheavy nuclei are thus theoretically predicted[43] and have so far been observed[44] to predominantly decay via decay modes that are caused by such repulsion: alpha decay and spontaneous fission.[g] Almost all alpha emitters have over 210 nucleons,[46] and the lightest nuclide primarily undergoing spontaneous fission has 238.[47] In both decay modes, nuclei are inhibited from decaying by corresponding energy barriers for each mode, but they can be tunneled through.[41][42]

Apparatus for creation of superheavy elements
Scheme of an apparatus for creation of superheavy elements, based on the Dubna Gas-Filled Recoil Separator set up in the Flerov Laboratory of Nuclear Reactions in JINR. The trajectory within the detector and the beam focusing apparatus changes because of a dipole magnet in the former and quadrupole magnets in the latter.[48]

Alpha particles are commonly produced in radioactive decays because the mass of an alpha particle per nucleon is small enough to leave some energy for the alpha particle to be used as kinetic energy to leave the nucleus.[49] Spontaneous fission is caused by electrostatic repulsion tearing the nucleus apart and produces various nuclei in different instances of identical nuclei fissioning.[42] As the atomic number increases, spontaneous fission rapidly becomes more important: spontaneous fission partial half-lives decrease by 23 orders of magnitude from uranium (element 92) to nobelium (element 102),[50] and by 30 orders of magnitude from thorium (element 90) to fermium (element 100).[51] The earlier liquid drop model thus suggested that spontaneous fission would occur nearly instantly due to disappearance of the fission barrier for nuclei with about 280 nucleons.[42][52] The later nuclear shell model suggested that nuclei with about 300 nucleons would form an island of stability in which nuclei will be more resistant to spontaneous fission and will primarily undergo alpha decay with longer half-lives.[42][52] Subsequent discoveries suggested that the predicted island might be further than originally anticipated; they also showed that nuclei intermediate between the long-lived actinides and the predicted island are deformed, and gain additional stability from shell effects.[53] Experiments on lighter superheavy nuclei,[54] as well as those closer to the expected island,[50] have shown greater than previously anticipated stability against spontaneous fission, showing the importance of shell effects on nuclei.[h]

Alpha decays are registered by the emitted alpha particles, and the decay products are easy to determine before the actual decay; if such a decay or a series of consecutive decays produces a known nucleus, the original product of a reaction can be easily determined.[i] (That all decays within a decay chain were indeed related to each other is established by the location of these decays, which must be in the same place.)[36] The known nucleus can be recognized by the specific characteristics of decay it undergoes such as decay energy (or more specifically, the kinetic energy of the emitted particle).[j] Spontaneous fission, however, produces various nuclei as products, so the original nuclide cannot be determined from its daughters.[k]

The information available to physicists aiming to synthesize a superheavy element is thus the information collected at the detectors: location, energy, and time of arrival of a particle to the detector, and those of its decay. The physicists analyze this data and seek to conclude that it was indeed caused by a new element and could not have been caused by a different nuclide than the one claimed. Often, provided data is insufficient for a conclusion that a new element was definitely created and there is no other explanation for the observed effects; errors in interpreting data have been made.[l]

History

Early predictions

The heaviest element known at the end of the 19th century was uranium, with an atomic mass of about 240 (now known to be 238) amu. Accordingly, it was placed in the last row of the periodic table; this fueled speculation about the possible existence of elements heavier than uranium and why A = 240 seemed to be the limit. Following the discovery of the noble gases, beginning with argon in 1895, the possibility of heavier members of the group was considered. Danish chemist Julius Thomsen proposed in 1895 the existence of a sixth noble gas with Z = 86, A = 212 and a seventh with Z = 118, A = 292, the last closing a 32-element period containing thorium and uranium.[65] In 1913, Swedish physicist Johannes Rydberg extended Thomsen's extrapolation of the periodic table to include even heavier elements with atomic numbers up to 460, but he did not believe that these superheavy elements existed or occurred in nature.[66]

In 1914, German physicist Richard Swinne proposed that elements heavier than uranium, such as those around Z = 108, could be found in cosmic rays. He suggested that these elements may not necessarily have decreasing half-lives with increasing atomic number, leading to speculation about the possibility of some longer-lived elements at Z = 98–102 and Z = 108–110 (though separated by short-lived elements). Swinne published these predictions in 1926, believing that such elements might exist in Earth's core, iron meteorites, or the ice caps of Greenland where they had been locked up from their supposed cosmic origin.[67]

Discoveries

Work performed from 1961 to 2013 at four labs – Lawrence Berkeley National Laboratory in the US, the Joint Institute for Nuclear Research in the USSR (later Russia), the GSI Helmholtz Centre for Heavy Ion Research in Germany, and Riken in Japan – identified and confirmed the elements lawrencium to oganesson according to the criteria of the IUPAC–IUPAP Transfermium Working Groups and subsequent Joint Working Parties. These discoveries complete the seventh row of the periodic table. The next two elements, ununennium (Z = 119) and unbinilium (Z = 120), have not yet been synthesized. They would begin an eighth period.

List of elements

Characteristics

Due to their short half-lives (for example, the most stable known isotope of seaborgium has a half-life of 14 minutes, and half-lives decrease with increasing atomic number) and the low yield of the nuclear reactions that produce them, new methods have had to be created to determine their gas-phase and solution chemistry based on very small samples of a few atoms each. Relativistic effects become very important in this region of the periodic table, causing the filled 7s orbitals, empty 7p orbitals, and filling 6d orbitals to all contract inward toward the atomic nucleus. This causes a relativistic stabilization of the 7s electrons and makes the 7p orbitals accessible in low excitation states.[20]

Elements 103 to 112, lawrencium to copernicium, form the 6d series of transition elements. Experimental evidence shows that elements 103–108 behave as expected for their position in the periodic table, as heavier homologs of lutetium through osmium. They are expected to have ionic radii between those of their 5d transition metal homologs and their actinide pseudohomologs: for example, Rf4+ is calculated to have ionic radius 76 pm, between the values for Hf4+ (71 pm) and Th4+ (94 pm). Their ions should also be less polarizable than those of their 5d homologs. Relativistic effects are expected to reach a maximum at the end of this series, at roentgenium (element 111) and copernicium (element 112). Nevertheless, many important properties of the transactinides are still not yet known experimentally, though theoretical calculations have been performed.[20]

Elements 113 to 118, nihonium to oganesson, should form a 7p series, completing the seventh period in the periodic table. Their chemistry will be greatly influenced by the very strong relativistic stabilization of the 7s electrons and a strong spin–orbit coupling effect "tearing" the 7p subshell apart into two sections, one more stabilized (7p1/2, holding two electrons) and one more destabilized (7p3/2, holding four electrons). Lower oxidation states should be stabilized here, continuing group trends, as both the 7s and 7p1/2 electrons exhibit the inert-pair effect. These elements are expected to largely continue to follow group trends, though with relativistic effects playing an increasingly larger role. In particular, the large 7p splitting results in an effective shell closure at flerovium (element 114) and a hence much higher than expected chemical activity for oganesson (element 118).[20]

Element 118 is the last element that has been synthesized. The next two elements, 119 and 120, should form an 8s series and be an alkali and alkaline earth metal respectively. The 8s electrons are expected to be relativistically stabilized, so that the trend toward higher reactivity down these groups will reverse and the elements will behave more like their period 5 homologs, rubidium and strontium. The 7p3/2 orbital is still relativistically destabilized, potentially giving these elements larger ionic radii and perhaps even being able to participate chemically. In this region, the 8p electrons are also relativistically stabilized, resulting in a ground-state 8s28p1 valence electron configuration for element 121. Large changes are expected to occur in the subshell structure in going from element 120 to element 121: for example, the radius of the 5g orbitals should drop drastically, from 25 Bohr units in element 120 in the excited [Og] 5g1 8s1 configuration to 0.8 Bohr units in element 121 in the excited [Og] 5g1 7d1 8s1 configuration, in a phenomenon called "radial collapse". Element 122 should add either a further 7d or a further 8p electron to element 121's electron configuration. Elements 121 and 122 should be similar to actinium and thorium respectively.[20]

At element 121, the superactinide series is expected to begin, when the 8s electrons and the filling 8p1/2, 7d3/2, 6f5/2, and 5g7/2 subshells determine the chemistry of these elements. Complete and accurate calculations are not available for elements beyond 123 because of the extreme complexity of the situation:[68] the 5g, 6f, and 7d orbitals should have about the same energy level, and in the region of element 160 the 9s, 8p3/2, and 9p1/2 orbitals should also be about equal in energy. This will cause the electron shells to mix so that the block concept no longer applies very well, and will also result in novel chemical properties that will make positioning these elements in a periodic table very difficult.[20]

Beyond superheavy elements

It has been suggested that elements beyond Z = 126 be called beyond superheavy elements.[69] Other sources refer to elements around Z = 164 as hyperheavy elements.[70]

See also

Notes

  1. ^ The most stable isotope of meitnerium cannot be determined based on existing data due to uncertainty that arises from the low number of measurements. The half-life of 278Mt corresponding to two standard deviations is, based on existing data, 4.5+7.0
    −2.6     seconds[3], whereas that of 274Mt is 0.64+1.52
    −0.46     seconds[4]; these measurements have overlapping confidence intervals. It is also possible that the unconfirmed 282Mt is more stable than both of these, with its half-life being 67 seconds.[5]
  2. ^ In nuclear physics, an element is called heavy if its atomic number is high; lead (element 82) is one example of such a heavy element. The term "superheavy elements" typically refers to elements with atomic number greater than 103 (although there are other definitions, such as atomic number greater than 100[22] or 112;[23] sometimes, the term is presented an equivalent to the term "transactinide", which puts an upper limit before the beginning of the hypothetical superactinide series).[24] Terms "heavy isotopes" (of a given element) and "heavy nuclei" mean what could be understood in the common language—isotopes of high mass (for the given element) and nuclei of high mass, respectively.
  3. ^ In 2009, a team at the JINR led by Oganessian published results of their attempt to create hassium in a symmetric 136Xe + 136Xe reaction. They failed to observe a single atom in such a reaction, putting the upper limit on the cross section, the measure of probability of a nuclear reaction, as 2.5 pb.[25] In comparison, the reaction that resulted in hassium discovery, 208Pb + 58Fe, had a cross section of ~20 pb (more specifically, 19+19
    -11     pb), as estimated by the discoverers.[26]
  4. ^ The amount of energy applied to the beam particle to accelerate it can also influence the value of cross section. For example, in the 28
    14    Si
     + 1
    0    n
     → 28
    13    Al
     + 1
    1    p
     reaction, cross section changes smoothly from 370 mb at 12.3 MeV to 160 mb at 18.3 MeV, with a broad peak at 13.5 MeV with the maximum value of 380 mb.[30]
  5. ^ This figure also marks the generally accepted upper limit for lifetime of a compound nucleus.[35]
  6. ^ This separation is based on that the resulting nuclei move past the target more slowly then the unreacted beam nuclei. The separator contains electric and magnetic fields whose effects on a moving particle cancel out for a specific velocity of a particle.[37] Such separation can also be aided by a time-of-flight measurement and a recoil energy measurement; a combination of the two may allow to estimate the mass of a nucleus.[38]
  7. ^ Not all decay modes are caused by electrostatic repulsion. For example, beta decay is caused by the weak interaction.[45]
  8. ^ It was already known by the 1960s that ground states of nuclei differed in energy and shape as well as that certain magic numbers of nucleons corresponded to greater stability of a nucleus. However, it was assumed that there was no nuclear structure in superheavy nuclei as they were too deformed to form one.[50]
  9. ^ Since mass of a nucleus is not measured directly but is rather calculated from that of another nucleus, such measurement is called indirect. Direct measurements are also possible, but for the most part they have remained unavailable for superheavy nuclei.[55] The first direct measurement of mass of a superheavy nucleus was reported in 2018 at LBNL.[56] Mass was determined from the location of a nucleus after the transfer (the location helps determine its trajectory, which is linked to the mass-to-charge ratio of the nucleus, since the transfer was done in presence of a magnet).[57]
  10. ^ If the decay occurred in a vacuum, then since total momentum of an isolated system before and after the decay must be preserved, the daughter nucleus would also receive a small velocity. The ratio of the two velocities, and accordingly the ratio of the kinetic energies, would thus be inverse to the ratio of the two masses. The decay energy equals the sum of the known kinetic energy of the alpha particle and that of the daughter nucleus (an exact fraction of the former).[46] The calculations hold for an experiment as well, but the difference is that the nucleus does not move after the decay because it is tied to the detector.
  11. ^ Spontaneous fission was discovered by Soviet physicist Georgy Flerov,[58] a leading scientist at JINR, and thus it was a "hobbyhorse" for the facility.[59] In contrast, the LBL scientists believed fission information was not sufficient for a claim of synthesis of an element. They believed spontaneous fission had not been studied enough to use it for identification of a new element, since there was a difficulty of establishing that a compound nucleus had only ejected neutrons and not charged particles like protons or alpha particles.[35] They thus preferred to link new isotopes to the already known ones by successive alpha decays.[58]
  12. ^ For instance, element 102 was mistakenly identified in 1957 at the Nobel Institute of Physics in Stockholm, Stockholm County, Sweden.[60] There were no earlier definitive claims of creation of this element, and the element was assigned a name by its Swedish, American, and British discoverers, nobelium. It was later shown that the identification was incorrect.[61] The following year, RL was unable to reproduce the Swedish results and announced instead their synthesis of the element; that claim was also disproved later.[61] JINR insisted that they were the first to create the element and suggested a name of their own for the new element, joliotium;[62] the Soviet name was also not accepted (JINR later referred to the naming of the element 102 as "hasty").[63] This name was proposed to IUPAC in a written response to their ruling on priority of discovery claims of elements, signed 29 September 1992.[63] The name "nobelium" remained unchanged on account of its widespread usage.[64]

References

  1. ^ Emsley, John (2003). Nature's Building Blocks. Oxford University Press. ISBN 978-0198503408. Retrieved November 12, 2012.
  2. ^ Meitnerium. The Periodic Table of Videos. University of Nottingham. February 18, 2010. Retrieved October 15, 2012.
  3. ^ a b Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  4. ^ Oganessian, Yu. Ts.; Utyonkov, V. K.; Kovrizhnykh, N. D.; et al. (2022). "New isotope 286Mc produced in the 243Am+48Ca reaction". Physical Review C. 106 (64306): 064306. Bibcode:2022PhRvC.106f4306O. doi:10.1103/PhysRevC.106.064306. S2CID 254435744.
  5. ^ a b Hofmann, S.; Heinz, S.; Mann, R.; Maurer, J.; Münzenberg, G.; Antalic, S.; Barth, W.; Burkhard, H. G.; Dahl, L.; Eberhardt, K.; Grzywacz, R.; Hamilton, J. H.; Henderson, R. A.; Kenneally, J. M.; Kindler, B.; Kojouharov, I.; Lang, R.; Lommel, B.; Miernik, K.; Miller, D.; Moody, K. J.; Morita, K.; Nishio, K.; Popeko, A. G.; Roberto, J. B.; Runke, J.; Rykaczewski, K. P.; Saro, S.; Scheidenberger, C.; Schött, H. J.; Shaughnessy, D. A.; Stoyer, M. A.; Thörle-Popiesch, P.; Tinschert, K.; Trautmann, N.; Uusitalo, J.; Yeremin, A. V. (2016). "Review of even element super-heavy nuclei and search for element 120". The European Physics Journal A. 2016 (52). doi:10.1140/epja/i2016-16180-4.
  6. ^ a b c d Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. ISBN 978-1-4020-3555-5.
  7. ^ Thierfelder, C.; Schwerdtfeger, P.; Heßberger, F. P.; Hofmann, S. (2008). "Dirac-Hartree-Fock studies of X-ray transitions in meitnerium". The European Physical Journal A. 36 (2): 227. Bibcode:2008EPJA...36..227T. doi:10.1140/epja/i2008-10584-7.
  8. ^ a b Östlin, A.; Vitos, L. (2011). "First-principles calculation of the structural stability of 6d transition metals". Physical Review B. 84 (11): 113104. Bibcode:2011PhRvB..84k3104O. doi:10.1103/PhysRevB.84.113104.
  9. ^ Gyanchandani, Jyoti; Sikka, S. K. (May 10, 2011). "Physical properties of the 6 d -series elements from density functional theory: Close similarity to lighter transition metals". Physical Review B. 83 (17): 172101. Bibcode:2011PhRvB..83q2101G. doi:10.1103/PhysRevB.83.172101.
  10. ^ Kratz; Lieser (2013). Nuclear and Radiochemistry: Fundamentals and Applications (3rd ed.). p. 631.
  11. ^ Fricke, Burkhard (1975). "Superheavy elements: a prediction of their chemical and physical properties". Recent Impact of Physics on Inorganic Chemistry. Structure and Bonding. 21: 89–144. doi:10.1007/BFb0116498. ISBN 978-3-540-07109-9. Retrieved October 4, 2013.
  12. ^ Chemical Data. Meitnerium - Mt, Royal Chemical Society
  13. ^ Saito, Shiro L. (2009). "Hartree–Fock–Roothaan energies and expectation values for the neutral atoms He to Uuo: The B-spline expansion method". Atomic Data and Nuclear Data Tables. 95 (6): 836–870. Bibcode:2009ADNDT..95..836S. doi:10.1016/j.adt.2009.06.001.
  14. ^ "Superheavy Element Discovery | Glenn T. Seaborg Institute". seaborg.llnl.gov. Retrieved September 2, 2024.
  15. ^ a b Neve, Francesco (2022). "Chemistry of superheavy transition metals". Journal of Coordination Chemistry. 75 (17–18): 2287–2307. doi:10.1080/00958972.2022.2084394. S2CID 254097024.
  16. ^ a b Mingos, Michael (1998). Essential Trends in Inorganic Chemistry. Oxford University Press. p. 387. ISBN 978-0-19-850109-1.
  17. ^ "A New Era of Discovery: the 2023 Long Range Plan for Nuclear Science" (PDF). U.S. Department of Energy. October 2023. Archived from the original (PDF) on October 5, 2023. Retrieved October 20, 2023 – via OSTI. Superheavy elements (Z > 102) are teetering at the limits of mass and charge.
  18. ^ Kragh, Helge (2017). "The search for superheavy elements: Historical and philosophical perspectives". arXiv:1708.04064 [physics.hist-ph].
  19. ^ IUPAC Provisional Recommendations for the Nomenclature of Inorganic Chemistry (2004) (online draft of an updated version of the "Red Book" IR 3-6) Archived October 27, 2006, at the Wayback Machine
  20. ^ a b c d e f Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean, eds. (2006). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer. ISBN 978-1-4020-3555-5.
  21. ^ "Kernchemie". www.kernchemie.de.
  22. ^ Krämer, K. (2016). "Explainer: superheavy elements". Chemistry World. Retrieved March 15, 2020.
  23. ^ "Discovery of Elements 113 and 115". Lawrence Livermore National Laboratory. Archived from the original on September 11, 2015. Retrieved March 15, 2020.
  24. ^ Eliav, E.; Kaldor, U.; Borschevsky, A. (2018). "Electronic Structure of the Transactinide Atoms". In Scott, R. A. (ed.). Encyclopedia of Inorganic and Bioinorganic Chemistry. John Wiley & Sons. pp. 1–16. doi:10.1002/9781119951438.eibc2632. ISBN 978-1-119-95143-8. S2CID 127060181.
  25. ^ Oganessian, Yu. Ts.; Dmitriev, S. N.; Yeremin, A. V.; et al. (2009). "Attempt to produce the isotopes of element 108 in the fusion reaction 136Xe + 136Xe". Physical Review C. 79 (2): 024608. doi:10.1103/PhysRevC.79.024608. ISSN 0556-2813.
  26. ^ Münzenberg, G.; Armbruster, P.; Folger, H.; et al. (1984). "The identification of element 108" (PDF). Zeitschrift für Physik A. 317 (2): 235–236. Bibcode:1984ZPhyA.317..235M. doi:10.1007/BF01421260. S2CID 123288075. Archived from the original (PDF) on June 7, 2015. Retrieved October 20, 2012.
  27. ^ Subramanian, S. (August 28, 2019). "Making New Elements Doesn't Pay. Just Ask This Berkeley Scientist". Bloomberg Businessweek. Retrieved January 18, 2020.
  28. ^ a b c d e f Ivanov, D. (2019). "Сверхтяжелые шаги в неизвестное" [Superheavy steps into the unknown]. nplus1.ru (in Russian). Retrieved February 2, 2020.
  29. ^ Hinde, D. (2017). "Something new and superheavy at the periodic table". The Conversation. Retrieved January 30, 2020.
  30. ^ Kern, B. D.; Thompson, W. E.; Ferguson, J. M. (1959). "Cross sections for some (n, p) and (n, α) reactions". Nuclear Physics. 10: 226–234. Bibcode:1959NucPh..10..226K. doi:10.1016/0029-5582(59)90211-1.
  31. ^ Wakhle, A.; Simenel, C.; Hinde, D. J.; et al. (2015). Simenel, C.; Gomes, P. R. S.; Hinde, D. J.; et al. (eds.). "Comparing Experimental and Theoretical Quasifission Mass Angle Distributions". European Physical Journal Web of Conferences. 86: 00061. Bibcode:2015EPJWC..8600061W. doi:10.1051/epjconf/20158600061. hdl:1885/148847. ISSN 2100-014X.
  32. ^ "Nuclear Reactions" (PDF). pp. 7–8. Retrieved January 27, 2020. Published as Loveland, W. D.; Morrissey, D. J.; Seaborg, G. T. (2005). "Nuclear Reactions". Modern Nuclear Chemistry. John Wiley & Sons, Inc. pp. 249–297. doi:10.1002/0471768626.ch10. ISBN 978-0-471-76862-3.
  33. ^ a b Krása, A. (2010). "Neutron Sources for ADS". Faculty of Nuclear Sciences and Physical Engineering. Czech Technical University in Prague: 4–8. S2CID 28796927.
  34. ^ Wapstra, A. H. (1991). "Criteria that must be satisfied for the discovery of a new chemical element to be recognized" (PDF). Pure and Applied Chemistry. 63 (6): 883. doi:10.1351/pac199163060879. ISSN 1365-3075. S2CID 95737691.
  35. ^ a b Hyde, E. K.; Hoffman, D. C.; Keller, O. L. (1987). "A History and Analysis of the Discovery of Elements 104 and 105". Radiochimica Acta. 42 (2): 67–68. doi:10.1524/ract.1987.42.2.57. ISSN 2193-3405. S2CID 99193729.
  36. ^ a b c d Chemistry World (2016). "How to Make Superheavy Elements and Finish the Periodic Table [Video]". Scientific American. Retrieved January 27, 2020.
  37. ^ Hoffman, Ghiorso & Seaborg 2000, p. 334.
  38. ^ Hoffman, Ghiorso & Seaborg 2000, p. 335.
  39. ^ Zagrebaev, Karpov & Greiner 2013, p. 3.
  40. ^ Beiser 2003, p. 432.
  41. ^ a b Pauli, N. (2019). "Alpha decay" (PDF). Introductory Nuclear, Atomic and Molecular Physics (Nuclear Physics Part). Université libre de Bruxelles. Retrieved February 16, 2020.
  42. ^ a b c d e Pauli, N. (2019). "Nuclear fission" (PDF). Introductory Nuclear, Atomic and Molecular Physics (Nuclear Physics Part). Université libre de Bruxelles. Retrieved February 16, 2020.
  43. ^ Staszczak, A.; Baran, A.; Nazarewicz, W. (2013). "Spontaneous fission modes and lifetimes of superheavy elements in the nuclear density functional theory". Physical Review C. 87 (2): 024320–1. arXiv:1208.1215. Bibcode:2013PhRvC..87b4320S. doi:10.1103/physrevc.87.024320. ISSN 0556-2813.
  44. ^ Audi et al. 2017, pp. 030001-129–030001-138.
  45. ^ Beiser 2003, p. 439.
  46. ^ a b Beiser 2003, p. 433.
  47. ^ Audi et al. 2017, p. 030001-125.
  48. ^ Aksenov, N. V.; Steinegger, P.; Abdullin, F. Sh.; et al. (2017). "On the volatility of nihonium (Nh, Z = 113)". The European Physical Journal A. 53 (7): 158. Bibcode:2017EPJA...53..158A. doi:10.1140/epja/i2017-12348-8. ISSN 1434-6001. S2CID 125849923.
  49. ^ Beiser 2003, p. 432–433.
  50. ^ a b c Oganessian, Yu. (2012). "Nuclei in the "Island of Stability" of Superheavy Elements". Journal of Physics: Conference Series. 337 (1): 012005-1–012005-6. Bibcode:2012JPhCS.337a2005O. doi:10.1088/1742-6596/337/1/012005. ISSN 1742-6596.
  51. ^ Moller, P.; Nix, J. R. (1994). Fission properties of the heaviest elements (PDF). Dai 2 Kai Hadoron Tataikei no Simulation Symposium, Tokai-mura, Ibaraki, Japan. University of North Texas. Retrieved February 16, 2020.
  52. ^ a b Oganessian, Yu. Ts. (2004). "Superheavy elements". Physics World. 17 (7): 25–29. doi:10.1088/2058-7058/17/7/31. Retrieved February 16, 2020.
  53. ^ Schädel, M. (2015). "Chemistry of the superheavy elements". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 373 (2037): 20140191. Bibcode:2015RSPTA.37340191S. doi:10.1098/rsta.2014.0191. ISSN 1364-503X. PMID 25666065.
  54. ^ Hulet, E. K. (1989). Biomodal spontaneous fission. 50th Anniversary of Nuclear Fission, Leningrad, USSR. Bibcode:1989nufi.rept...16H.
  55. ^ Oganessian, Yu. Ts.; Rykaczewski, K. P. (2015). "A beachhead on the island of stability". Physics Today. 68 (8): 32–38. Bibcode:2015PhT....68h..32O. doi:10.1063/PT.3.2880. ISSN 0031-9228. OSTI 1337838. S2CID 119531411.
  56. ^ Grant, A. (2018). "Weighing the heaviest elements". Physics Today. doi:10.1063/PT.6.1.20181113a. S2CID 239775403.
  57. ^ Howes, L. (2019). "Exploring the superheavy elements at the end of the periodic table". Chemical & Engineering News. Retrieved January 27, 2020.
  58. ^ a b Robinson, A. E. (2019). "The Transfermium Wars: Scientific Brawling and Name-Calling during the Cold War". Distillations. Retrieved February 22, 2020.
  59. ^ "Популярная библиотека химических элементов. Сиборгий (экавольфрам)" [Popular library of chemical elements. Seaborgium (eka-tungsten)]. n-t.ru (in Russian). Retrieved January 7, 2020. Reprinted from "Экавольфрам" [Eka-tungsten]. Популярная библиотека химических элементов. Серебро – Нильсборий и далее [Popular library of chemical elements. Silver through nielsbohrium and beyond] (in Russian). Nauka. 1977.
  60. ^ "Nobelium - Element information, properties and uses | Periodic Table". Royal Society of Chemistry. Retrieved March 1, 2020.
  61. ^ a b Kragh 2018, pp. 38–39.
  62. ^ Kragh 2018, p. 40.
  63. ^ a b Ghiorso, A.; Seaborg, G. T.; Oganessian, Yu. Ts.; et al. (1993). "Responses on the report 'Discovery of the Transfermium elements' followed by reply to the responses by Transfermium Working Group" (PDF). Pure and Applied Chemistry. 65 (8): 1815–1824. doi:10.1351/pac199365081815. S2CID 95069384. Archived (PDF) from the original on November 25, 2013. Retrieved September 7, 2016.
  64. ^ Commission on Nomenclature of Inorganic Chemistry (1997). "Names and symbols of transfermium elements (IUPAC Recommendations 1997)" (PDF). Pure and Applied Chemistry. 69 (12): 2471–2474. doi:10.1351/pac199769122471.
  65. ^ Kragh 2018, p. 6
  66. ^ Kragh 2018, p. 7
  67. ^ Kragh 2018, p. 10
  68. ^ van der Schoor, K. (2016). Electronic structure of element 123 (PDF) (Thesis). Rijksuniversiteit Groningen.
  69. ^ Hofmann, Sigurd (2019). "Synthesis and properties of isotopes of the transactinides". Radiochimica Acta. 107 (9–11): 879–915. doi:10.1515/ract-2019-3104. S2CID 203848120.
  70. ^ Laforge, Evan; Price, Will; Rafelski, Johann (2023). "Superheavy elements and ultradense matter". The European Physical Journal Plus. 138 (9): 812. arXiv:2306.11989. Bibcode:2023EPJP..138..812L. doi:10.1140/epjp/s13360-023-04454-8.

Bibliography

History

Meitnerium was named after the physicist Lise Meitner, one of the discoverers of nuclear fission.

Discovery

Meitnerium was first synthesized on August 29, 1982 by a German research team led by Peter Armbruster and Gottfried Münzenberg at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung) in Darmstadt.[1] The team bombarded a target of bismuth-209 with accelerated nuclei of iron-58 and detected a single atom of the isotope meitnerium-266:[2]

209
83Bi
 + 58
26Fe
 → 266
109Mt
 +
n

This work was confirmed three years later at the Joint Institute for Nuclear Research at Dubna (then in the Soviet Union).[2]

Naming

File:Bohrium hassium meitnerium ceremony.jpg
Naming ceremony conducted at the GSI on 7 September 1992 for the namings of elements 107, 108, and 109 as nielsbohrium, hassium, and meitnerium

Using Mendeleev's nomenclature for unnamed and undiscovered elements, meitnerium should be known as eka-iridium. In 1979, during the Transfermium Wars (but before the synthesis of meitnerium), IUPAC published recommendations according to which the element was to be called unnilennium (with the corresponding symbol of Une),[3] a systematic element name as a placeholder, until the element was discovered (and the discovery then confirmed) and a permanent name was decided on. Although widely used in the chemical community on all levels, from chemistry classrooms to advanced textbooks, the recommendations were mostly ignored among scientists in the field, who either called it "element 109", with the symbol of E109, (109) or even simply 109, or used the proposed name "meitnerium".[4]

The naming of meitnerium was discussed in the element naming controversy regarding the names of elements 104 to 109, but meitnerium was the only proposal and thus was never disputed.[5][6] The name meitnerium (Mt) was suggested by the GSI team in September 1992 in honor of the Austrian physicist Lise Meitner, a co-discoverer of protactinium (with Otto Hahn),[7][8][9][10][11] and one of the discoverers of nuclear fission.[12] In 1994 the name was recommended by IUPAC,[5] and was officially adopted in 1997.[6] It is thus the only element named specifically after a non-mythological woman (curium being named for both Pierre and Marie Curie).[13]

Isotopes

Main article: Isotopes of meitnerium

Meitnerium has no stable or naturally occurring isotopes. Several radioactive isotopes have been synthesized in the laboratory, either by fusing two atoms or by observing the decay of heavier elements. Eight different isotopes of meitnerium have been reported with atomic masses 266, 268, 270, and 274–278, two of which, meitnerium-268 and meitnerium-270, have known but unconfirmed metastable states. A ninth isotope with atomic mass 282 is unconfirmed. Most of these decay predominantly through alpha decay, although some undergo spontaneous fission.[14]

Stability and half-lives

All meitnerium isotopes are extremely unstable and radioactive; in general, heavier isotopes are more stable than the lighter. The most stable known meitnerium isotope, 278Mt, is also the heaviest known; it has a half-life of 4.5 seconds. The unconfirmed 282Mt is even heavier and appears to have a longer half-life of 67 seconds. The isotopes 276Mt and 274Mt have half-lives of 0.45 and 0.44 seconds respectively. The remaining five isotopes have half-lives between 1 and 20 milliseconds.[14]

The isotope 277Mt, created as the final decay product of 293Ts for the first time in 2012, was observed to undergo spontaneous fission with a half-life of 5 milliseconds. Preliminary data analysis considered the possibility of this fission event instead originating from 277Hs, for it also has a half-life of a few milliseconds, and could be populated following undetected electron capture somewhere along the decay chain.[15][16] This possibility was later deemed very unlikely based on observed decay energies of 281Ds and 281Rg and the short half-life of 277Mt, although there is still some uncertainty of the assignment.[16] Regardless, the rapid fission of 277Mt and 277Hs is strongly suggestive of a region of instability for superheavy nuclei with N = 168–170. The existence of this region, characterized by a decrease in fission barrier height between the deformed shell closure at N = 162 and spherical shell closure at N = 184, is consistent with theoretical models.[15]

List of meitnerium isotopes
Isotope Half-life[a] Decay
mode 		Discovery
year 		Discovery
reaction
Value ref
266Mt 1.2 ms [17] α, SF 1982 209Bi(58Fe,n)
268Mt 27 ms [17] α 1994 272Rg(—,α)
270Mt 6.3 ms [17] α 2004 278Nh(—,2α)
274Mt 440 ms [18] α 2006 282Nh(—,2α)
275Mt 20 ms [18] α 2003 287Mc(—,3α)
276Mt 450 ms [18] α 2003 288Mc(—,3α)
277Mt 5 ms [18] SF 2012 293Ts(—,4α)
278Mt 4.5 s [18] α 2010 294Ts(—,4α)
282Mt[b] 1.1 min [19] α 1998 290Fl(e−,νe2α)

Predicted properties

No properties of meitnerium or its compounds have been measured; this is due to its extremely limited and expensive production[20] and the fact that meitnerium and its parents decay very quickly. Properties of meitnerium metal remain unknown and only predictions are available.

Chemical

Meitnerium is the seventh member of the 6d series of transition metals. Since element 112 (copernicium) has been shown to be a group 12 metal, it is expected that all the elements from 104 to 111 would continue a fourth transition metal series, with meitnerium as part of the platinum group metals.[10] Calculations on its ionization potentials and atomic and ionic radii are similar to that of its lighter homologue iridium, thus implying that meitnerium's basic properties will resemble those of the other group 9 elements, cobalt, rhodium, and iridium.[4]

Prediction of the probable chemical properties of meitnerium has not received much attention recently. Meitnerium is expected to be a noble metal, and about as noble as silver (the standard electrode potential for the Mt3+/Mt couple is expected to be 0.8 V, close to the +0.7993 V value known for the Ag+/Ag couple). Based on the most stable oxidation states of the lighter group 9 elements, the most stable oxidation states of meitnerium are predicted to be the +6, +3, and +1 states, with the +3 state being the most stable in aqueous solutions. In comparison, rhodium and iridium show a maximum oxidation state of +6, while the most stable states are +4 and +3 for iridium and +3 for rhodium.[4] The oxidation state +9, represented only by iridium in [IrO4]+, might be possible for its congener meitnerium in the nonafluoride (MtF9) and the [MtO4]+ cation, although [IrO4]+ is expected to be more stable than these meitnerium compounds.[21] The tetrahalides of meitnerium have also been predicted to have similar stabilities to those of iridium, thus also allowing a stable +4 state.[22] It is further expected that the maximum oxidation states of elements from bohrium (element 107) to darmstadtium (element 110) may be stable in the gas phase but not in aqueous solution.[4]

Physical and atomic

Meitnerium is expected to be a solid under normal conditions and assume a face-centered cubic crystal structure, similarly to its lighter congener iridium.[23] It should be a very heavy metal with a density of around 37.4 g/cm3, which would be the second-highest of any of the 118 known elements, second only to that predicted for its neighbor hassium (41 g/cm3). In comparison, the densest known element that has had its density measured, osmium, has a density of only 22.61 g/cm3. This results from meitnerium's high atomic weight, the lanthanide and actinide contractions, and relativistic effects, although production of enough meitnerium to measure this quantity would be impractical, and the sample would quickly decay.[4] Meitnerium is also predicted to be paramagnetic.[24]

Theoreticians have predicted the covalent radius of meitnerium to be 6 to 10 pm larger than that of iridium.[25] The atomic radius of meitnerium is expected to be around 128 pm.[26]

Experimental chemistry

Meitnerium is the first element on the periodic table whose chemistry has not yet been investigated. Unambiguous determination of the chemical characteristics of meitnerium has yet to have been established[27][28] due to the short half-lives of meitnerium isotopes[4] and a limited number of likely volatile compounds that could be studied on a very small scale. One of the few meitnerium compounds that are likely to be sufficiently volatile is meitnerium hexafluoride (MtF
6), as its lighter homologue iridium hexafluoride (IrF
6) is volatile above 60 °C and therefore the analogous compound of meitnerium might also be sufficiently volatile;[10] a volatile octafluoride (MtF
8) might also be possible.[4] For chemical studies to be carried out on a transactinide, at least four atoms must be produced, the half-life of the isotope used must be at least 1 second, and the rate of production must be at least one atom per week.[10] Even though the half-life of 278Mt, the most stable confirmed meitnerium isotope, is 4.5 seconds, long enough to perform chemical studies, another obstacle is the need to increase the rate of production of meitnerium isotopes and allow experiments to carry on for weeks or months so that statistically significant results can be obtained. Separation and detection must be carried out continuously to separate out the meitnerium isotopes and have automated systems experiment on the gas-phase and solution chemistry of meitnerium, as the yields for heavier elements are predicted to be smaller than those for lighter elements; some of the separation techniques used for bohrium and hassium could be reused. However, the experimental chemistry of meitnerium has not received as much attention as that of the heavier elements from copernicium to livermorium.[4][27][29]

The Lawrence Berkeley National Laboratory attempted to synthesize the isotope 271Mt in 2002–2003 for a possible chemical investigation of meitnerium because it was expected that it might be more stable than the isotopes around it as it has 162 neutrons, a magic number for deformed nuclei; its half-life was predicted to be a few seconds, long enough for a chemical investigation.[4][30][31] However, no atoms of 271Mt were detected,[32] and this isotope of meitnerium is currently unknown.[14]

An experiment determining the chemical properties of a transactinide would need to compare a compound of that transactinide with analogous compounds of some of its lighter homologues:[4] for example, in the chemical characterization of hassium, hassium tetroxide (HsO4) was compared with the analogous osmium compound, osmium tetroxide (OsO4).[33] In a preliminary step towards determining the chemical properties of meitnerium, the GSI attempted sublimation of the rhodium compounds rhodium(III) oxide (Rh2O3) and rhodium(III) chloride (RhCl3). However, macroscopic amounts of the oxide would not sublimate until 1000 °C and the chloride would not until 780 °C, and then only in the presence of carbon aerosol particles: these temperatures are far too high for such procedures to be used on meitnerium, as most of the current methods used for the investigation of the chemistry of superheavy elements do not work above 500 °C.[28]

Following the 2014 successful synthesis of seaborgium hexacarbonyl, Sg(CO)6,[34] studies were conducted with the stable transition metals of groups 7 through 9, suggesting that carbonyl formation could be extended to further probe the chemistries of the early 6d transition metals from rutherfordium to meitnerium inclusive.[35][36] Nevertheless, the challenges of low half-lives and difficult production reactions make meitnerium difficult to access for radiochemists, though the isotopes 278Mt and 276Mt are long-lived enough for chemical research and may be produced in the decay chains of 294Ts and 288Mc respectively. 276Mt is likely more suitable, since producing tennessine requires a rare and rather short-lived berkelium target.[37] The isotope 270Mt, observed in the decay chain of 278Nh with a half-life of 0.69 seconds, may also be sufficiently long-lived for chemical investigations, though a direct synthesis route leading to this isotope and more precise measurements of its decay properties would be required.[31]

Notes

  1. ^ Different sources give different values for half-lives; the most recently published values are listed.
  2. ^ This isotope is unconfirmed

References

  1. ^ Münzenberg, G.; Armbruster, P.; Heßberger, F. P.; Hofmann, S.; Poppensieker, K.; Reisdorf, W.; Schneider, J. H. R.; Schneider, W. F. W.; Schmidt, K.-H.; Sahm, C.-C.; Vermeulen, D. (1982). "Observation of one correlated α-decay in the reaction 58Fe on 209Bi→267109". Zeitschrift für Physik A. 309 (1): 89. Bibcode:1982ZPhyA.309...89M. doi:10.1007/BF01420157.
  2. ^ a b Barber, R. C.; Greenwood, N. N.; Hrynkiewicz, A. Z.; Jeannin, Y. P.; Lefort, M.; Sakai, M.; Ulehla, I.; Wapstra, A. P.; Wilkinson, D. H. (1993). "Discovery of the transfermium elements. Part II: Introduction to discovery profiles. Part III: Discovery profiles of the transfermium elements". Pure and Applied Chemistry. 65 (8): 1757. doi:10.1351/pac199365081757. (Note: for Part I see Pure Appl. Chem., Vol. 63, No. 6, pp. 879–886, 1991)
  3. ^ 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.
  4. ^ a b c d e f g h i j Cite error: The named reference Haire was invoked but never defined (see the help page).
  5. ^ a b "Names and symbols of transfermium elements (IUPAC Recommendations 1994)". Pure and Applied Chemistry. 66 (12): 2419–2421. 1994. doi:10.1351/pac199466122419.
  6. ^ a b Cite error: The named reference IUPAC97 was invoked but never defined (see the help page).
  7. ^ Bentzen, S. M. (2000). "Lise Meitner and Niels Bohr—a historical note". Acta Oncologica. 39 (8): 1002–1003. doi:10.1080/02841860050216016. PMID 11206992.
  8. ^ Kyle, R. A.; Shampo, M. A. (1981). "Lise Meitner". JAMA: The Journal of the American Medical Association. 245 (20): 2021. doi:10.1001/jama.245.20.2021. PMID 7014939.
  9. ^ Frisch, O. R. (1973). "Distinguished Nuclear Pioneer—1973. Lise Meitner". Journal of Nuclear Medicine. 14 (6): 365–371. PMID 4573793.
  10. ^ a b c d Griffith, W. P. (2008). "The Periodic Table and the Platinum Group Metals". Platinum Metals Review. 52 (2): 114–119. doi:10.1595/147106708X297486.
  11. ^ Rife, Patricia (2003). "Meitnerium". Chemical & Engineering News. 81 (36): 186. doi:10.1021/cen-v081n036.p186.
  12. ^ Wiesner, Emilie; Settle, Frank A. (2001). "Politics, Chemistry, and the Discovery of Nuclear Fission". Journal of Chemical Education. 78 (7): 889. Bibcode:2001JChEd..78..889W. doi:10.1021/ed078p889.
  13. ^ "Meitnerium is named for the Austrian physicist Lise Meitner." in Meitnerium in Royal Society of Chemistry – Visual Element Periodic Table. Retrieved August 14, 2015.
  14. ^ a b c Sonzogni, Alejandro. "Interactive Chart of Nuclides". National Nuclear Data Center: Brookhaven National Laboratory. Retrieved June 6, 2008.
  15. ^ a b Oganessian, Yuri Ts.; Abdullin, F. Sh.; Alexander, C.; Binder, J.; Boll, R. A.; Dmitriev, S. N.; Ezold, J.; Felker, K.; Gostic, J. M. (May 30, 2013). "Experimental studies of the 249Bk + 48Ca reaction including decay properties and excitation function for isotopes of element 117, and discovery of the new isotope 277Mt". Physical Review C. 87 (54621). American Physical Society: 054621. Bibcode:2013PhRvC..87e4621O. doi:10.1103/PhysRevC.87.054621. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  16. ^ a b Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch.E.; Ackermann, D.; Andersson, L.-L.; Asai, M.; Block, M.; Boll, R.A.; Brand, H.; et al. (2019). "Fusion reaction 48Ca+249Bk leading to formation of the element Ts (Z = 117)" (PDF). Physical Review C. 99 (5): 054306–1–054306–16. Bibcode:2019PhRvC..99e4306K. doi:10.1103/PhysRevC.99.054306.
  17. ^ a b c Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.
  18. ^ a b c d e Oganessian, Y.T. (2015). "Super-heavy element research". Reports on Progress in Physics. 78 (3): 036301. Bibcode:2015RPPh...78c6301O. doi:10.1088/0034-4885/78/3/036301. PMID 25746203. {{cite journal}}: Invalid |ref=harv (help)
  19. ^ Cite error: The named reference Hofmann2016 was invoked but never defined (see the help page).
  20. ^ Cite error: The named reference Bloomberg was invoked but never defined (see the help page).
  21. ^ Cite error: The named reference Mt(IX) was invoked but never defined (see the help page).
  22. ^ Cite error: The named reference MtX4 was invoked but never defined (see the help page).
  23. ^ Cite error: The named reference bcc was invoked but never defined (see the help page).
  24. ^ Cite error: The named reference paramagnetic was invoked but never defined (see the help page).
  25. ^ Pyykkö, Pekka; Atsumi, Michiko (2009). "Molecular Double-Bond Covalent Radii for Elements Li—E112". Chemistry: A European Journal. 15 (46): 12770–9. doi:10.1002/chem.200901472. PMID 19856342.
  26. ^ Cite error: The named reference BFricke was invoked but never defined (see the help page).
  27. ^ a b Düllmann, Christoph E. (2012). "Superheavy elements at GSI: a broad research program with element 114 in the focus of physics and chemistry". Radiochimica Acta. 100 (2): 67–74. doi:10.1524/ract.2011.1842.
  28. ^ a b Haenssler, F. L.; Düllmann, Ch. E.; Gäggeler, H. W.; Eichler, B. "Thermatographic investigation of Rh and 107Rh with different carrier gases" (PDF). Retrieved October 15, 2012.[permanent dead link]
  29. ^ Eichler, Robert (2013). "First foot prints of chemistry on the shore of the Island of Superheavy Elements". Journal of Physics: Conference Series. 420 (1). IOP Science: 012003. arXiv:1212.4292. Bibcode:2013JPhCS.420a2003E. doi:10.1088/1742-6596/420/1/012003.
  30. ^ Smolańczuk, R. (1997). "Properties of the hypothetical spherical superheavy nuclei". Phys. Rev. C. 56 (2): 812–24. Bibcode:1997PhRvC..56..812S. doi:10.1103/PhysRevC.56.812.
  31. ^ a b Even, J.; et al. (2015). "In situ synthesis of volatile carbonyl complexes with short-lived nuclides". Journal of Radioanalytical and Nuclear Chemistry. 303 (3): 2457–2466. doi:10.1007/s10967-014-3793-7.
  32. ^ Zielinski P. M. et al. (2003). "The search for 271Mt via the reaction 238U + 37Cl" Archived 2012-02-06 at the Wayback Machine, GSI Annual report. Retrieved on 2008-03-01
  33. ^ Düllmann, Ch. E for a Univ. Bern - PSI - GSI - JINR - LBNL - Univ. Mainz - FZR - IMP - collaboration. "Chemical investigation of hassium (Hs, Z=108)" (PDF). Archived from the original (PDF) on February 2, 2014. Retrieved October 15, 2012.
  34. ^ Even, J.; Yakushev, A.; Dullmann, C. E.; Haba, H.; Asai, M.; Sato, T. K.; Brand, H.; Di Nitto, A.; Eichler, R.; Fan, F. L.; Hartmann, W.; Huang, M.; Jager, E.; Kaji, D.; Kanaya, J.; Kaneya, Y.; Khuyagbaatar, J.; Kindler, B.; Kratz, J. V.; Krier, J.; Kudou, Y.; Kurz, N.; Lommel, B.; Miyashita, S.; Morimoto, K.; Morita, K.; Murakami, M.; Nagame, Y.; Nitsche, H.; et al. (2014). "Synthesis and detection of a seaborgium carbonyl complex". Science. 345 (6203): 1491–3. Bibcode:2014Sci...345.1491E. doi:10.1126/science.1255720. PMID 25237098. (subscription required)
  35. ^ Loveland, Walter (September 19, 2014). "Superheavy carbonyls". Science. 345 (6203): 1451–2. Bibcode:2014Sci...345.1451L. doi:10.1126/science.1259349. PMID 25237088.
  36. ^ Even, Julia (2016). Chemistry aided nuclear physics studies (PDF). Nobel Symposium NS160 – Chemistry and Physics of Heavy and Superheavy Elements. doi:10.1051/epjconf/201613107008.
  37. ^ Moody, Ken (November 30, 2013). "Synthesis of Superheavy Elements". In Schädel, Matthias; Shaughnessy, Dawn (eds.). The Chemistry of Superheavy Elements (2nd ed.). Springer Science & Business Media. pp. 24–8. ISBN 9783642374661.

Bibliography

Retrieved from "https://en.wikipedia.org/w/index.php?title=Meitnerium&oldid=964591509"