Periodic table › Dubnium
1. Identity and classification
Lustrous, hard, high-density silvery or metallic solid with high tensile strength
- Name and symbol
- Dubnium (Dubnium) · Db
- Atomic number
- 105
- Relative atomic weight / mass number
- [268]
- Group · period · block
- 5 · 7 · d
- Category
- Transition Metal
- State near room temperature
- Unknown
- Stable isotopes
- No stable isotopes
- CAS number
- 53850-35-4
Square brackets [A] indicate a representative isotope mass number, not an average atomic weight. Neutron counts differ between isotopes.
2. Atomic structure and electron configuration
- Protons · electrons in a neutral atom
- 105 · 105
- Neutrons in reference isotope
- 163 (268Db)
- Full electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 5f¹⁴ 6d³ 7s²- Abbreviated configuration
[Rn]7s² 5f¹⁴ 6d³- Electrons per shell
- 2, 8, 18, 32, 32, 11, 2
- Listed oxidation states
- 5, 4, 3
- Electronegativity
- Not established
- First ionization energy
- Not established · Not established
- Electron affinity
- Not established
- Covalent radius
- 149 pm
- van der Waals radius
- Not established
Configurations of superheavy elements may include theoretical predictions. Different definitions of atomic radius are not interchangeable.
3. Physical and thermal properties
- Density
- Not established
- Melting point
- Not established
- Boiling point
- Not established
- Crystal structure
- Unknown / Predicted
- Specific heat
- Not established
- Thermal conductivity
- Not established
- Enthalpy of fusion
- Not established
- Enthalpy of vaporization
- Not established
- Magnetic ordering
- Unknown
- Mohs hardness
- Not established
- Speed of sound
- Not established
Density and structure depend on temperature, pressure and allotrope. 25°C is a room-temperature reference, not STP. Unestablished values are not zero.
4. Chemical behavior and compounds
Bulk reactions are not established; experiments involve small numbers of radioactive atoms.
Selected compounds: DbO / Db₂O₃ (Oxide) · DbClₙ (Chloride) · DbFₙ (Fluoride)
Reaction reference
Bulk reactions are not established; experiments involve small numbers of radioactive atoms.
Bulk reactions are not established; experiments involve small numbers of radioactive atoms.
5. Isotopes
| Isotope | Status | Natural abundance | Half-life |
|---|---|---|---|
| 268Db | Radioactive | — | 28 h |
Half-life units: s seconds, m minutes, h hours, d days, Y years. A dash means no natural-abundance value is given, not zero. Listed records are selected ground states; metastable states are distinct.
6. Discovery and occurrence
- Discovery
- 1967 CE
- Scientists associated with discovery
- Joint Institute for Nuclear Research (Dubna) & Lawrence Berkeley National Lab (1970)
- Location
- USSR (Dubna) / USA (Berkeley)
- Origin
- Synthetic
- Listed crustal abundance
- 0 ppm
Minerals and naming reference
Synthesized via heavy-ion fusion (²⁴⁹Cf + ¹⁵N)
Named from scientific/historical roots associated with Dubnium (Db), discovered or characterized by Joint Institute for Nuclear Research (Dubna) & Lawrence Berkeley National Lab (1970).
7. Applications
Single-atom chemical studies of DbOCl₃ and DbCl₅ investigating Group 5 relativistic deviations from Nb and Ta
Detailed applications by field
- everyday
- Single-atom chemical studies of DbOCl₃ and DbCl₅ investigating Group 5 relativistic deviations from Nb and Ta
- industry
- Used in transition metal processing, specialized alloys, and chemical manufacturing (Single-atom chemical studies of DbOCl₃ and DbCl₅ investigating Group 5 relativistic deviations from Nb and Ta).
- electronics
- Applied in electronic components, semiconductors, or functional coatings where Dubnium's electronic structure ([Rn] 5f¹⁴ 6d³ 7s²) provides target conductivity.
- medicine
- Restricted to controlled nuclear medicine or fundamental radiochemical research.
- energy
- Utilized in power generation, battery materials, catalysts, or nuclear technology involving Dubnium.
- aerospace
- High-performance materials, structural alloys, or space instrumentation utilizing Dubnium.
- agriculture
- Not used in agriculture due to radioactivity or heavy-metal toxicity.
- science
- Spectroscopic standard, crystallography, and quantum chemistry studies of Period 7 d-block elements.
8. Biological role and safety
Hazard depends on the isotope, chemical form, dose and exposure route.
Elemental substances, ions, compounds and radioisotopes can have different health effects. This is an educational reference; laboratory work requires the material safety data sheet and trained supervision.
Biological role reference
Classified as highly radioactive / synthetic in human and biological systems.