Element 45
Rhodium (Rh)
Rhodium (Rh) is element 45 of the periodic table, a transition metal in period 5, group 9 (d-block) with an atomic mass of 102.91 and is a solid at standard conditions.
At a glance
- Atomic number
- 45
- Symbol
- Rh
- Atomic mass
- 102.91 u
- Category
- Transition metals
- Period
- 5
- Group
- 9
- Block
- d-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d8 5s1
- Shorthand configuration
- [Kr] 4d8 5s1
- Electrons per shell
- 2, 8, 18, 16, 1
- Oxidation states
- -3, -1, +1, +2, +3, +4, +5, +6
Physical properties
- Melting point
- 2,237 K (1,963.85 °C)
- Boiling point
- 3,968 K (3,694.85 °C)
- Density
- 12.41 g/cm³
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 2.28
- Atomic radius
- 173 pm
- Covalent radius
- 142 pm
- First ionization energy
- 720 kJ/mol
- Electron affinity
- 110 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Rh-103 | 102.9055 | 100% | Stable |
Common uses
- Catalytic converters
- Jewelry
- Electrical contacts
- Mirrors
Discovery
- Year
- 1803
- Discovered by
- William Hyde Wollaston
- Country
- England
Frequently asked questions
- Is rhodium a metal?
- Yes. Rhodium is a metal, classified as a transition metal on the periodic table.
- How many protons does rhodium have?
- Rhodium has 45 protons. Its atomic number is 45, which is also the number of electrons in a neutral atom of rhodium.
- What group and period is rhodium in?
- Rhodium is in group 9 and period 5 of the periodic table, in the d-block.
- What is the atomic mass of rhodium?
- The atomic mass of rhodium is 102.91 u (unified atomic mass units).
Keep exploring
Rhodium's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.