Nihonium

  • nihonium, 113nh
    nihonium
    pronunciationm/ (hoh-nee-əm)
    mass number[286]
    nihonium 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
    tl

    nh

    (uhs)
    coperniciumnihoniumflerovium
    atomic number (z)113
    groupgroup 13 (boron group)
    periodperiod 7
    blockp-block
    element category  unknown chemical properties, but probably a post-transition metal; possibly a metalloid[1]
    electron configuration[rn] 5f14 6d10 7s2 7p1 (predicted)[2]
    electrons per shell2, 8, 18, 32, 32, 18, 3 (predicted)
    physical properties
    phase at stpsolid (predicted)[2][3][4]
    melting point700 k ​(430 °c, ​810 °f) (predicted)[2]
    boiling point1430 k ​(1130 °c, ​2070 °f) (predicted)[2][5]
    density (near r.t.)16 g/cm3 (predicted)[5]
    heat of fusion7.61 kj/mol (extrapolated)[4]
    heat of vaporisation130 kj/mol (predicted)[3][5]
    atomic properties
    oxidation states(−1), (+1), (+3), (+5) (predicted)[2][5][6]
    ionisation energies
    • 1st: 704.9 kj/mol (predicted)[2]
    • 2nd: 2240 kj/mol (predicted)[5]
    • 3rd: 3020 kj/mol (predicted)[5]
    • (more)
    atomic radiusempirical: 170 pm (predicted)[2]
    covalent radius172–180 pm (extrapolated)[4]
    other properties
    natural occurrencesynthetic
    crystal structurehexagonal close-packed (hcp)
    hexagonal close-packed crystal structure for nihonium

    (extrapolated)[7]
    cas number54084-70-7
    history
    namingafter japan (nihon in japanese)
    discoveryriken (japan, first undisputed claim 2004)
    jinr (russia) and livermore (us, first announcement 2003)
    main isotopes of nihonium
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    278nh syn 1.4 ms α 274rg
    282nh syn 73 ms α 278rg
    283nh syn 75 ms α 279rg
    284nh syn 0.91 s α 280rg
    ec 284cn
    285nh syn 4.2 s α 281rg
    286nh syn 9.5 s α 282rg
    287nh[8] syn 5.5 s? α 283rg
    290nh[9] syn 2 s? α 286rg
    category category: nihonium
    | references

    nihonium is a synthetic chemical element with the symbol nh and atomic number 113. it is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. in the periodic table, nihonium is a transactinide element in the p-block. it is a member of period 7 and group 13 (boron group).

    nihonium was first reported to have been created in 2003 by a russian–american collaboration at the joint institute for nuclear research (jinr) in dubna, russia, and in 2004 by a team of japanese scientists at riken in wakō, japan. the confirmation of their claims in the ensuing years involved independent teams of scientists working in the united states, germany, sweden, and china, as well as the original claimants in russia and japan. in 2015, the iupac/iupap joint working party recognised the element and assigned the priority of the discovery and naming rights for the element to riken, as it judged that they had demonstrated that they had observed element 113 before the jinr team did so. the riken team suggested the name nihonium in 2016, which was approved in the same year. the name comes from the common japanese name for japan (日本, nihon).

    very little is known about nihonium, as it has only been made in very small amounts that decay away within seconds. the anomalously long lives of some superheavy nuclides, including some nihonium isotopes, are explained by the "island of stability" theory. experiments support the theory, with the half-lives of the confirmed nihonium isotopes increasing from milliseconds to seconds as neutrons are added and the island is approached. nihonium has been calculated to have similar properties to its homologues boron, aluminium, gallium, indium, and thallium. all but boron are post-transition metals, and nihonium is expected to be a post-transition metal as well. it should also show several major differences from them; for example, nihonium should be more stable in the +1 oxidation state than the +3 state, like thallium, but in the +1 state nihonium should behave more like silver and astatine than thallium. preliminary experiments in 2017 showed that elemental nihonium is not very volatile; its chemistry remains largely unexplored.

  • introduction
  • history
  • isotopes
  • predicted properties
  • experimental chemistry
  • see also
  • notes
  • references
  • bibliography
  • external links

Nihonium, 113Nh
Nihonium
Pronunciationm/ (HOH-nee-əm)
Mass number[286]
Nihonium 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
Tl

Nh

(Uhs)
coperniciumnihoniumflerovium
Atomic number (Z)113
Groupgroup 13 (boron group)
Periodperiod 7
Blockp-block
Element category  Unknown chemical properties, but probably a post-transition metal; possibly a metalloid[1]
Electron configuration[Rn] 5f14 6d10 7s2 7p1 (predicted)[2]
Electrons per shell2, 8, 18, 32, 32, 18, 3 (predicted)
Physical properties
Phase at STPsolid (predicted)[2][3][4]
Melting point700 K ​(430 °C, ​810 °F) (predicted)[2]
Boiling point1430 K ​(1130 °C, ​2070 °F) (predicted)[2][5]
Density (near r.t.)16 g/cm3 (predicted)[5]
Heat of fusion7.61 kJ/mol (extrapolated)[4]
Heat of vaporisation130 kJ/mol (predicted)[3][5]
Atomic properties
Oxidation states(−1), (+1), (+3), (+5) (predicted)[2][5][6]
Ionisation energies
  • 1st: 704.9 kJ/mol (predicted)[2]
  • 2nd: 2240 kJ/mol (predicted)[5]
  • 3rd: 3020 kJ/mol (predicted)[5]
  • (more)
Atomic radiusempirical: 170 pm (predicted)[2]
Covalent radius172–180 pm (extrapolated)[4]
Other properties
Natural occurrencesynthetic
Crystal structurehexagonal close-packed (hcp)
Hexagonal close-packed crystal structure for nihonium

(extrapolated)[7]
CAS Number54084-70-7
History
NamingAfter Japan (Nihon in Japanese)
DiscoveryRiken (Japan, first undisputed claim 2004)
JINR (Russia) and Livermore (US, first announcement 2003)
Main isotopes of nihonium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
278Nh syn 1.4 ms α 274Rg
282Nh syn 73 ms α 278Rg
283Nh syn 75 ms α 279Rg
284Nh syn 0.91 s α 280Rg
EC 284Cn
285Nh syn 4.2 s α 281Rg
286Nh syn 9.5 s α 282Rg
287Nh[8] syn 5.5 s? α 283Rg
290Nh[9] syn 2 s? α 286Rg
Category Category: Nihonium
| references

Nihonium is a synthetic chemical element with the symbol Nh and atomic number 113. It is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block. It is a member of period 7 and group 13 (boron group).

Nihonium was first reported to have been created in 2003 by a Russian–American collaboration at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, and in 2004 by a team of Japanese scientists at Riken in Wakō, Japan. The confirmation of their claims in the ensuing years involved independent teams of scientists working in the United States, Germany, Sweden, and China, as well as the original claimants in Russia and Japan. In 2015, the IUPAC/IUPAP Joint Working Party recognised the element and assigned the priority of the discovery and naming rights for the element to Riken, as it judged that they had demonstrated that they had observed element 113 before the JINR team did so. The Riken team suggested the name nihonium in 2016, which was approved in the same year. The name comes from the common Japanese name for Japan (日本, nihon).

Very little is known about nihonium, as it has only been made in very small amounts that decay away within seconds. The anomalously long lives of some superheavy nuclides, including some nihonium isotopes, are explained by the "island of stability" theory. Experiments support the theory, with the half-lives of the confirmed nihonium isotopes increasing from milliseconds to seconds as neutrons are added and the island is approached. Nihonium has been calculated to have similar properties to its homologues boron, aluminium, gallium, indium, and thallium. All but boron are post-transition metals, and nihonium is expected to be a post-transition metal as well. It should also show several major differences from them; for example, nihonium should be more stable in the +1 oxidation state than the +3 state, like thallium, but in the +1 state nihonium should behave more like silver and astatine than thallium. Preliminary experiments in 2017 showed that elemental nihonium is not very volatile; its chemistry remains largely unexplored.