045Transition metal · Group 9 · Period 5
Rhodium
Rhodium (Rh) is element 45, a transition metal in the d-block — group 9, period 5. It is a solid at room temperature with 5 electron shells (2, 8, 18, 16, 1) and an atomic mass of 102.905502 u.
- Atomic mass
- 102.9 u
- Phase · STP
- solid
- Melting
- 2237 K · 1964 °C
- Boiling
- 3968 K · 3695 °C
- Electronegativity
- 2.28
- Density
- 12.41 g/cm³
Photograph — Hi-Res Images ofChemical Elements, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/rhodium.php
Identity
- Atomic number
- 45
- Standard atomic weight
- 102.9 u
- Category
- Transition metal
- Group
- 9
- Period
- 5
- Block
- d-block
- Oxidation states
- +3
Physical properties
- Melting point
- 2237 K · 1964 °C
- Boiling point
- 3968 K · 3695 °C
- Density
- 12.41 g/cm³
- Molar heat capacity
- 24.98 J/(mol·K)
- Atomic radius
- 195 pm
- Electron affinity
- 110.27 kJ/mol
Atomic structure
45protons
58neutrons
45electrons
1valence e⁻
- Noble-gas notation
- [Kr] 4d8 5s1
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1 4d8
- Electrons per shell
- 2, 8, 18, 16, 1
Periodic trends
Where Rhodium ranks across all 118 elements.
Ionization energies
Energy to remove each successive electron (kJ/mol).
719.71
1.7k2
3.0k3
Successive ionization energies (kJ/mol, log scale).
Discovery
- Discovered
- 1803
- Discovered by
- William Hyde Wollaston
- Named by
- —
- Appearance
- silvery white metallic