105Transition metal · Group 5 · Period 7
Dubnium
Dubnium (Db) is element 105, a transition metal in the d-block — group 5, period 7. It is a solid at room temperature with 7 electron shells (2, 8, 18, 32, 32, 11, 2) and an atomic mass of 268 u.
- Atomic mass
- 268.0 u
- Phase · STP
- solid
- Melting
- —
- Boiling
- —
- Electronegativity
- —
- Density
- 29.3 g/cm³
Photograph — Chemical Elements A Virtual Museum under a Creative Commons Attribution 3.0 Unported License, source: https://images-of-elements.com/dubnium.php
Identity
- Atomic number
- 105
- Standard atomic weight
- 268.0 u
- Category
- Transition metal
- Group
- 5
- Period
- 7
- Block
- d-block
- Oxidation states
- 5, 4, 3
Physical properties
- Melting point
- —
- Boiling point
- —
- Density
- 29.3 g/cm³
- Molar heat capacity
- —
- Atomic radius
- —
- Electron affinity
- —
Atomic structure
105protons
163neutrons
105electrons
2valence e⁻
- Noble-gas notation
- *[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
Periodic trends
Where Dubnium ranks across all 118 elements.
Discovery
- Discovered
- 1967
- Discovered by
- Joint Institute for Nuclear Research
- Named by
- —
- Appearance
- —