Db
Dubnium
Element 105 · Transition metal
Dubnium (Db)
Dubnium is a synthetic, radioactive transition metal studied a few atoms at a time.
- Transition metal
- Period 7
- Group 5
- d-block
- solid at room temperature
- ☢ Radioactive
Key properties
- Atomic mass
- [268]
- u
- Electron configuration
- [Rn] 5f14 6d3 7s2
- Melting point
- —
- Boiling point
- —
- Density
- 29.3 g/cm³
- Electronegativity
- —
- Atomic radius
- —
- 1st ionisation energy
- —
Superheavy elements have only been made a few atoms at a time. Most properties shown are theoretical predictions.
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about dubnium
- 01
It was called hahnium by American scientists for many years.
- 02
Its name was finally settled by IUPAC in 1997.
- 03
Experiments show it behaves like niobium and tantalum, the elements above it.
Applications
What is dubnium used for?
- Research
History
Discovery & name origin
Discovered by
Year
Where
Russia and United States
Name origin
From Dubna, the Russian town home to the Joint Institute for Nuclear Research.
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 105
- Atomic mass
- [268] u
- Group
- 5
- Period
- 7
- Block
- d-block
- Electron configuration
- [Rn] 5f14 6d3 7s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d3
- Electrons per shell
- 2, 8, 18, 32, 32, 11, 2
- Electronegativity (Pauling)
- —
- Electron affinity
- —
- Atomic radius (van der Waals)
- —
- Stable isotopes
- None — all isotopes are radioactive
Oxidation states
Highlighted: common oxidation states (+5, +4, +3).
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid (predicted)
- Melting point
- —
- Boiling point
- —
- Density
- 29.3 g/cm³
- Molar heat capacity
- —
- Appearance
- —
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Dubnium questions
What is Db on the periodic table?
Db is the symbol for dubnium, element 105 on the periodic table. It sits in group 5, period 7, in the transition metal category, and has an atomic mass of [268].
What is the atomic number of dubnium?
Dubnium has atomic number 105, so every dubnium atom has 105 protons in its nucleus. Its symbol is Db and its atomic mass is [268].
Who discovered dubnium?
Dubnium was discovered by Georgy Flerov and Albert Ghiorso in 1968 (Russia and United States). The name comes from from Dubna, the Russian town home to the Joint Institute for Nuclear Research.
What is dubnium used for?
Dubnium is used for: research.
Is dubnium a metal?
Yes. Dubnium is a transition metal, one of the metallic elements.
What is the electron configuration of dubnium?
The electron configuration of dubnium is [Rn] 5f14 6d3 7s2 (predicted). Its 105 electrons are arranged in shells as 2, 8, 18, 32, 32, 11, 2.