Dubnium (Db)
Transition metal · Radioactive · Synthetic
Dubnium is named after Dubna, the Russian research town whose Joint Institute for Nuclear Research created many superheavy elements. Its longest-lived isotope survives about a day — long enough for chemistry.
Position on the periodic table
Atomic properties
| Atomic number | 105 |
|---|---|
| Atomic mass | 268 amu |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d3 |
| Noble gas shorthand | *[Rn] 5f14 6d3 7s2 |
| Electrons per shell | 2, 8, 18, 32, 32, 11, 2 |
| Valence electrons (outer shell) | 2 |
| Common oxidation states | +5 |
| Electronegativity (Pauling) | Not available |
| Covalent radius (approx.) | Not available |
| First ionization energy | Not available |
| Electron affinity | Not available |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Density | 29.3 g/cm³ |
| Melting point | Not available |
| Boiling point | Not available |
| Appearance | Not available |
| Radioactive | Yes |
| Origin | Synthetic (lab-made) |
Electron configuration of dubnium
Dubnium's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d3, usually shortened to *[Rn] 5f14 6d3 7s2. Its electrons occupy 7 shells (2, 8, 18, 32, 32, 11, 2), placing it in period 7 of the d-block. Explore it interactively in the electron configuration calculator.
Uses of dubnium
- Fundamental research only
Biological role: None.
Occurrence: Entirely synthetic.
History and discovery
Discovered: 1968 — Joint Institute for Nuclear Research. Name origin: Named after Dubna, Russia.
Synthesised at Dubna and Berkeley from 1968–70; named dubnium by IUPAC in 1997.
Safety notes
Radioactive; research only.
Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.
Practice questions
Quick practice: Dubnium
1. What is the chemical symbol of Dubnium?
2. What is the atomic number of Dubnium?
3. Which category does Dubnium belong to?
4. What is the state of Dubnium at room temperature?
5. Which period of the periodic table is Dubnium in?
Dubnium FAQs
What is the atomic number of dubnium?
Dubnium's atomic number is 105 — every dubnium atom has 105 protons in its nucleus.
What is the symbol for dubnium?
Db. Named after Dubna, Russia.
Is dubnium a metal, nonmetal, or metalloid?
Dubnium is classified as a transition metal.
What state is dubnium at room temperature?
At about 25 °C, dubnium is a solid.
What is dubnium used for?
Key uses include: fundamental research only.
Related elements
Keep working with this element
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