Rhodium (Rh)
Transition metal · d-block · period 5 · group 9
Hard, silvery-white, highly reflective metal.
Rhodium (symbol Rh) is chemical element number 45, a transition metal in group 9, period 5 of the periodic table. Its standard atomic weight is 102.91 and its electron configuration is [Kr] 4d8 5s1. At room temperature it is a solid. Its name is Greek for 'rose', after the pink colour of its salts.
Properties
| Atomic number | 45 |
|---|---|
| Atomic mass | 102.91 |
| Category | Transition metal |
| Block | d-block |
| Group · Period | 9 · 5 |
| Electron configuration | [Kr] 4d8 5s1 |
| Electrons per shell | 2, 8, 18, 16, 1 |
| State at 25 °C | solid |
| Melting point | 2237 K |
| Boiling point | 3968 K |
| Density | 12.41 g/cm³ |
| Electronegativity (Pauling) | 2.28 |
| Radioactive | No |
| Origin | primordial |
| Discovered | 1804 · William Hyde Wollaston |
Key facts about Rhodium
- Its name is Greek for 'rose', after the pink colour of its salts.
- Usually the single most expensive precious metal, at times worth many times more than gold.
- The key metal in the catalytic converter that cleans up car exhaust.
- White-gold jewellery is plated with rhodium for a bright white shine.
What Rhodium is used for
Catalytic converters, jewellery plating, hard mirror coatings, chemical catalysts, thermocouples.
Where it sits in the periodic table
Rhodium is in group 9, period 5, of the d-block. Its electron configuration [Kr] 4d8 5s1 means its outermost shell holds 1 electron, which is what places it here and explains much of its chemistry. See Rhodium on the interactive table →
Rhodium — frequently asked questions
What is Rhodium used for?
Catalytic converters, jewellery plating, hard mirror coatings, chemical catalysts, thermocouples.
Is Rhodium radioactive?
No. Rhodium has at least one stable isotope and is not radioactive.
What is the electron configuration of Rhodium?
Rhodium has the electron configuration [Kr] 4d8 5s1, which is 2, 8, 18, 16, 1 electrons per shell.
What group and period is Rhodium in?
Rhodium is in group 9, period 5, in the d-block. Its outer shell holds 1 electron.
Who discovered Rhodium?
Rhodium was discovered in 1804 by William Hyde Wollaston.