From Wikipedia, the free encyclopediaMeitnerium is a chemical element with symbol Mt and atomic number 109. It is an extremely radioactive synthetic element (an element not found in nature that can be created in a laboratory). The most stable known isotope, meitnerium-278, has a half-life of 7.6 seconds. | |||||||||||
Meitnerium in the periodic table | |||||||||||
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Symbol | Mt | ||||||||||
Atomic number | 109 | ||||||||||
Group | 9 | ||||||||||
Period | 7 | ||||||||||
Block | d | ||||||||||
Element category | Unknown | ||||||||||
Physical properties | |||||||||||
Phase at STP | Solid | ||||||||||
Density | 37.4 g/cm3 | ||||||||||
Atomic weight | 278 u | ||||||||||
Melting point | - | ||||||||||
Boiling point | K °C °F | ||||||||||
Atomic properties | |||||||||||
Electronegativity (Pauling Scale) | |||||||||||
Electron affinity | kJ/mol | ||||||||||
Oxidation states | (+1), (+3), (+4), (+6), (+8), (+9) (predicted) | ||||||||||
Ionization energies |
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Electron configuration | |||||||||||
Elektronkonfiguration (shorthand) | [Rn] 5f14 6d7 7s2 | ||||||||||
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d7 7s2 | ||||||||||
Electrons per shell | 2, 8, 18, 32, 32, 15, 2 | ||||||||||
History | |||||||||||
Discovered | 1982 | ||||||||||
Discovered by | Gesellschaft für Schwerionenforschung |