Dubnium (Db)

From Wikipedia, the free encyclopediaDubnium is a chemical element with symbol Db and atomic number 105. It is named after the town of Dubna in Russia (north of Moscow), where it was first produced. It is a synthetic element (an element that can be created in a laboratory but is not found in nature) and radioactive; the most stable known isotope, dubnium-268, has a half-life of approximately 28 hours.

Dubnium in the periodic table

SymbolDb
Atomic number105
Group5
Period7
Blockd
Element categoryTransition Metal

Physical properties

Phase at STPSolid
Density29.3 g/cm3
Atomic weight268 u
Melting point K
°C
°F
Boiling point K
°C
°F

Atomära egenskaper

Electronegativity (Pauling Scale)
Electron affinity kJ/mol
Ionization energies
1 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d3 7s2
Electrons per shell2, 8, 18, 32, 32, 11, 2

History

Discovered1970
Discovered byJoint Institute for Nuclear Research