45102.91RhRhodium
Rhodium (Rh) — element 45transition metal · group 9, period 5
Rhodium is a chemical element with the symbol Rh and atomic number 45. It is a transition metal in group 9, period 5 of the periodic table (the d-block), with a standard atomic mass of 102.91 u. At room temperature (25 °C) rhodium is a solid.
💡 Known for: One of the rarest and most valuable precious metals, used mainly in catalytic converters.
# Rhodium properties
| Symbol | Rh |
|---|---|
| Atomic number | 45 |
| Atomic mass | 102.91 u |
| Category | transition metal |
| Group | 9 |
| Period | 5 |
| Block | d-block |
| Electron configuration | [Kr] 4d⁸ 5s¹ |
| Full configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁸ 5s¹ |
| Electrons per shell | 2, 8, 18, 16, 1 |
| Protons / electrons | 45 / 45 |
| State at 25 °C | solid |
| Melting point | 2237 K (1963.8 °C, 3566.9 °F) |
| Boiling point | 3968 K (3694.8 °C, 6682.7 °F) |
| Density | 12.41 g/cm³ |
| Electronegativity (Pauling) | 2.28 |
| First ionization energy | 7.459 eV |
| Atomic radius | 173 pm |
| Discovered | 1803 |
# Electron configuration of rhodium
The electron configuration of rhodium is [Kr] 4d⁸ 5s¹, written out in full as 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁸ 5s¹. Its 45 electrons fill 5 shells as 2, 8, 18, 16, 1, so the outermost shell holds 1 electron.
# Related elements
RuRutheniumprevious elementPdPalladiumnext elementCoCobaltgroup 9IrIridiumgroup 9MtMeitneriumgroup 9ScScandiumtransition metalTiTitaniumtransition metalVVanadiumtransition metalCrChromiumtransition metalMnManganesetransition metalFeIrontransition metalNiNickeltransition metalCuCoppertransition metal
# Rhodium FAQ
What is the atomic number of rhodium?
The atomic number of rhodium is 45: every rhodium atom has 45 protons in its nucleus. Its symbol is Rh.
What is the atomic mass of rhodium?
The standard atomic mass of rhodium is 102.91 u.
What is the electron configuration of rhodium?
Rhodium's electron configuration is [Kr] 4d⁸ 5s¹ (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁸ 5s¹), with 2, 8, 18, 16, 1 electrons per shell.
Is rhodium a metal?
Yes. Rhodium is a transition metal, one of the metals.
What is the melting point of rhodium?
Rhodium melts at 2237 K (1963.8 °C, 3566.9 °F) and boils at 3968 K (3694.8 °C, 6682.7 °F).
What is rhodium used for / known for?
One of the rarest and most valuable precious metals, used mainly in catalytic converters.