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About Dubnium

Dubnium Bohr

Dubnium was produced in the 1960s by laboratories in both California and the former Soviet Union, leading to a protracted battle over naming rights that lasted until 1997. This 37-year debate has been referred to as the Transfermium Wars, as it concerned elements following fermium on the periodic table. Element 105 was finally named for the Joint Institute for Nuclear Research in Dubna, Russia in a compromise of sorts. Dubnium has no commercial applications.

Dubnium Properties

Dubinium Bohr ModelDubnium is a D-Block, Group 5, Period 7 element. The number of electrons in each of Dubnium's shells is 2, 8, 18, 32, 32, 11, 2 and its electron configuration is [Rn] 5f14 6d3 7s2. In its elemental form, Dubnium's CAS number 53850-35-4. Dubnium’s appearance is unknown but it is thought to be silvery white or metallic gray. Little is known about the element and it has no known uses. Dubnium is a synthetic element and therefore is not naturally found in the environment. The discovery of Dubnium was made independently by Russian researchers at the Joint Institute for Nuclear Research in 1967 and then by American researchers at the University of California, Berkeley in 1970. Dubnium is named after Dubna, Russia, where it was first discovered.

Dubnium information, including technical data, properties, and other useful facts are specified below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity, and thermal properties are included.

Symbol: Db
Atomic Number: 105
Atomic Weight: 268
Element Category: transition metal
Group, Period, Block: 5, 7, d
Color: unknown (presumably metallic/ silvery white/ gray)
Other Names: Dubnio
Melting Point: N/A
Boiling Point: N/A
Density: 29 (predicted)
Liquid Density @ Melting Point: N/A
Density @ 20°C: N/A
Density of Solid: 21600 (predicted) kg·m3
Specific Heat: N/A
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): N/A
Heat of Vaporization (kJ·mol-1): N/A
Heat of Atomization (kJ·mol-1): N/A
Thermal Conductivity: 0.58 W/cmK
Thermal Expansion: N/A
Electrical Resistivity: N/A
Tensile Strength: N/A
Molar Heat Capacity: N/A
Young's Modulus: N/A
Shear Modulus: N/A
Bulk Modulus: N/A
Poisson Ratio: N/A
Mohs Hardness: N/A
Vickers Hardness: N/A
Brinell Hardness: N/A
Speed of Sound: N/A
Pauling Electronegativity: N/A
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: N/A
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: N/A
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 105
Protons: 105
Neutrons: 157
Electron Configuration: [Rn] 5f14 6d3 7s2
Atomic Radius: 139 (estimated)
Atomic Radius,
non-bonded (Å):
Covalent Radius: 149 (estimated)
Covalent Radius (Å): 1.49
Van der Waals Radius: N/A
Oxidation States: 5, 4, 3 (predicted)
Phase: Solid (predicted)
Crystal Structure: N/A
Magnetic Ordering: N/A
Electron Affinity (kJ·mol-1) Unknown
1st Ionization Energy: 664.8 kJ·mol-1 (estimated)
2nd Ionization Energy: 1546.7 kJ·mol-1
3rd Ionization Energy: 2378.4 kJ·mol-1
CAS Number: 53850-35-4
EC Number: N/A
MDL Number: N/A
Beilstein Number: N/A
SMILES Identifier: [Db]
InChI Identifier: InChI=1S/Db
PubChem CID: 56951718
ChemSpider ID: N/A
Earth - Total: N/A
Mercury - Total: N/A
Venus - Total: N/A
Earth - Seawater (Oceans), ppb by weight: N/A
Earth - Seawater (Oceans), ppb by atoms: N/A
Earth -  Crust (Crustal Rocks), ppb by weight: N/A
Earth -  Crust (Crustal Rocks), ppb by atoms: N/A
Sun - Total, ppb by weight: N/A
Sun - Total, ppb by atoms: N/A
Stream, ppb by weight: N/A
Stream, ppb by atoms: N/A
Meterorite (Carbonaceous), ppb by weight: N/A
Meterorite (Carbonaceous), ppb by atoms: N/A
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: N/A
Universe, ppb by atom: N/A
Discovered By: Joint Institute for Nuclear Research
Discovery Date: 1970
First Isolation: N/A

Dubnium Isotopes

Dubnium (Db) is an artificial element. Like all artificial elements, it has no stable isotopes.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
255Db 255.10740(45)# 1.7(5) s [1.6(+6-4) s] a to 251Lr; SF N/A N/A 1849.09 -
256Db 256.10813(31)# 1.9(4) s [1.6(+5-3) s] a to 252Lr; SF ; EC to 256Rf N/A N/A 1857.17 -
257Db 257.10772(24)# 1.53(17) s [1.50(+19-15) s] a to 253Lr; SF ; EC to 257Rf (9/2+) N/A 1865.25 -
258Db 258.10923(37)# 4.5(6) s a to 254Lr; SF ; EC to 258Rf N/A N/A 1873.33 -
259Db 259.10961(23)# 0.51(16) s a to 255Lr N/A N/A 1881.41 -
260Db 260.11130(25)# 1.52(13) s a to 256Lr; SF ; EC to 260Rf N/A N/A 1880.17 -
261Db 261.11206(25)# 1.8(4) s a to 257Lr; SF N/A N/A 1888.25 -
262Db 262.11408(20)# 35(5) s a to 258Lr; SF ; EC to 262Rf N/A N/A 1896.33 -
263Db 263.11499(18)# 29(9) s [27(+10-7) s] a to 259Lr; SF N/A N/A 1904.4 -
264Db 264.11740(25)# 3# min Unknown N/A N/A 1912.48 -
265Db 265.1186(3)# 15# min Unknown N/A N/A 1920.56 -
266Db 266.12103(39)# 20# min Unknown N/A N/A 1919.32 -
267Db 267.12238(50)# 73(+350-33) min Unknown N/A N/A 1927.4 -
268Db 268.12545(57)# 32(+11-7) h Unknown N/A N/A 1935.48 -
269Db 269.12746(83)# 3# h Unknown N/A N/A 1943.56 -
270Db 270.13071(77)# 1# h Unknown N/A N/A 1942.32 -