Element 105 · Transition metal
Dubnium (Db) — Element 105
Dubna, Russia
Dubnium (Db) is a transition metal in Period 7, Group 5 of the periodic table with atomic number 105, standard atomic weight [268] u, and ground-state electron configuration [Rn] 5f¹⁴ 6d³ 7s². At standard temperature and pressure it is classified as a short-lived synthetic nuclide with 5 valence electrons and common oxidation states +5.
Research only
What are the atomic properties and physical constants of Dubnium?
Reference constants compiled from IUPAC standard atomic weights, the NIST Atomic Spectra Database, and the CRC Handbook.
- Atomic number (Z)
- 105
- Standard atomic mass
- [268] u
- Chemical family
- Transition metal
- Ground-state configuration
- [Rn] 5f¹⁴ 6d³ 7s²
- Electrons per shell
- 2, 8, 18, 32, 32, 11, 2
- Valence electrons
- 5
- Common ion charges / oxidation states
- +5
- Phase at STP
- Synthetic
- Pauling electronegativity
- —
- First ionization energy
- —
- Atomic radius
- —
- Melting point
- —
- Boiling point
- —
- Discovery year
- 1970
- Table coordinate
- Period 7, Group 5
- Radioactivity
- Radioactive (no stable isotopes)
How are electrons arranged across Dubnium’s shells?
A neutral Dubnium atom contains 105 electrons distributed across 7 occupied principal energy shells ([Rn] 5f¹⁴ 6d³ 7s²). The table below compares Dubnium’s shell occupancy against each shell’s theoretical 2n² capacity.
| Principal Shell (n) | Spectroscopic Letter | Electrons in Db | Max Shell Capacity (2n²) |
|---|---|---|---|
| n = 1 | K | 2 e⁻ | 2 e⁻ |
| n = 2 | L | 8 e⁻ | 8 e⁻ |
| n = 3 | M | 18 e⁻ | 18 e⁻ |
| n = 4 | N | 32 e⁻ | 32 e⁻ |
| n = 5 | O | 32 e⁻ | 50 e⁻ |
| n = 6 | P | 11 e⁻ | 72 e⁻ |
| n = 7 | Q | 2 e⁻ | 98 e⁻ |
Frequently Asked Questions about Dubnium (Db)
What is the atomic mass and atomic number of Dubnium (Db)?
Dubnium (Db) has atomic number Z = 105 (105 protons in its nucleus) and an IUPAC standard atomic weight of [268] u. It sits in Period 7, Group 5 and is classified as a transition metal.
What is the ground-state electron configuration of Dubnium?
The neutral ground-state electron configuration of Dubnium (Z = 105) is [Rn] 5f¹⁴ 6d³ 7s². Across its 7 occupied principal shells (n = 1 to n = 7), the electrons per shell are 2, 8, 18, 32, 32, 11, 2, with 5 valence electrons participating in bonding.
What are the common ion charges and electronegativity of Dubnium?
Dubnium commonly forms +5 oxidation states or ion charges in compounds. Its Pauling electronegativity is — and its first ionization energy is —.
When was Dubnium discovered and what is it used for?
Dubnium was discovered in 1970 (Dubna, Russia). Research only
How does Dubnium compare to neighboring elements?
Other transition metal elements: