Ruthenium (Ru)
Transition metal · d-block · period 5 · group 8
Hard, brittle, silvery-white platinum-group metal.
Ruthenium (symbol Ru) is chemical element number 44, a transition metal in group 8, period 5 of the periodic table. Its standard atomic weight is 101.07 and its electron configuration is [Kr] 4d7 5s1. At room temperature it is a solid. Named after Ruthenia, the Latin name for Russia.
Properties
| Atomic number | 44 |
|---|---|
| Atomic mass | 101.07 |
| Category | Transition metal |
| Block | d-block |
| Group · Period | 8 · 5 |
| Electron configuration | [Kr] 4d7 5s1 |
| Electrons per shell | 2, 8, 18, 15, 1 |
| State at 25 °C | solid |
| Melting point | 2607 K |
| Boiling point | 4423 K |
| Density | 12.45 g/cm³ |
| Electronegativity (Pauling) | 2.2 |
| Radioactive | No |
| Origin | primordial |
| Discovered | 1844 · Karl Ernst Claus |
Key facts about Ruthenium
- Named after Ruthenia, the Latin name for Russia.
- A few percent added to platinum or palladium makes them far harder and more wear-resistant.
- A superb catalyst — it helps split water and make ammonia.
- Ruthenium films store the data on modern hard-disk drives.
What Ruthenium is used for
Hard electrical contacts, hard-disk coatings, catalysts, wear-resistant platinum alloys, solar-cell dyes.
Where it sits in the periodic table
Ruthenium is in group 8, period 5, of the d-block. Its electron configuration [Kr] 4d7 5s1 means its outermost shell holds 1 electron, which is what places it here and explains much of its chemistry. See Ruthenium on the interactive table →
Ruthenium — frequently asked questions
What is Ruthenium used for?
Hard electrical contacts, hard-disk coatings, catalysts, wear-resistant platinum alloys, solar-cell dyes.
Is Ruthenium radioactive?
No. Ruthenium has at least one stable isotope and is not radioactive.
What is the electron configuration of Ruthenium?
Ruthenium has the electron configuration [Kr] 4d7 5s1, which is 2, 8, 18, 15, 1 electrons per shell.
What group and period is Ruthenium in?
Ruthenium is in group 8, period 5, in the d-block. Its outer shell holds 1 electron.
Who discovered Ruthenium?
Ruthenium was discovered in 1844 by Karl Ernst Claus.