Seaborgium

Seaborgium is a synthetic chemical element; it has symbol Sg and atomic number 106. It is named after the American nuclear chemist Glenn T. Seaborg. As a synthetic element, it can be created in a laboratory but is not found in nature. It is also radioactive; the most stable known isotope, 269Sg, has a half-life of approximately 14 minutes.

Seaborgium, 106Sg
Seaborgium
Pronunciation/sˈbɔːrɡiəm/ (see-BOR-ghee-əm)
Mass number[269]
Seaborgium 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
W

Sg

(Uhn)
dubniumseaborgiumbohrium
Atomic number (Z)106
Groupgroup 6
Periodperiod 7
Block  d-block
Electron configuration[Rn] 5f14 6d4 7s2
Electrons per shell2, 8, 18, 32, 32, 12, 2
Physical properties
Phase at STPsolid (predicted)
Density (near r.t.)23–24 g/cm3 (predicted)
Atomic properties
Oxidation states0, (+3), (+4), (+5), +6 (parenthesized: prediction)
Ionization energies
  • 1st: 757 kJ/mol
  • 2nd: 1733 kJ/mol
  • 3rd: 2484 kJ/mol
  • (more) (all but first estimated)
Atomic radiusempirical: 132 pm (predicted)
Covalent radius143 pm (estimated)
Other properties
Natural occurrencesynthetic
Crystal structure body-centered cubic (bcc)

(predicted)
CAS Number54038-81-2
History
Namingafter Glenn T. Seaborg
DiscoveryLawrence Berkeley National Laboratory (1974)
Isotopes of seaborgium
Main isotopes Decay
abun­dance half-life (t1/2) mode pro­duct
265Sg synth 8.5 s α 261Rf
265mSg synth 14.4 s α 261mRf
267Sg synth 80 s α17% 263Rf
SF83%
268Sg synth 13 s SF
269Sg synth 14 min α 265Rf
271Sg synth 31 s α73% 267Rf
SF27%

In the periodic table of the elements, it is a d-block transactinide element. It is a member of the 7th period and belongs to the group 6 elements as the fourth member of the 6d series of transition metals. Chemistry experiments have confirmed that seaborgium behaves as the heavier homologue to tungsten in group 6. The chemical properties of seaborgium are characterized only partly, but they compare well with the chemistry of the other group 6 elements.

In 1974, a few atoms of seaborgium were produced in laboratories in the Soviet Union and in the United States. The priority of the discovery and therefore the naming of the element was disputed between Soviet and American scientists, and it was not until 1997 that the International Union of Pure and Applied Chemistry (IUPAC) established seaborgium as the official name for the element. It is one of only two elements named after a living person at the time of naming, the other being oganesson, element 118.

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