Ruthenium is a platinum-group metal used in electrical components, catalysts, and durable alloys. Ruthenium oxide coatings serve on electrodes for chlorine production. These uses connect resistance to wear with the ability of a material's surface to support useful chemical and electrochemical reactions.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
Why add ruthenium to a platinum or palladium electrical contact?
Ruthenium-alloyed platinum or palladium
FOLLOW THIS RELATIONSHIP
Identify the contact matrix
Platinum or palladium supplies the main alloy framework. Ruthenium is added within that metal combination rather than placed beside an independent contact.
Explore the model (optional)
RuFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
What does the ruthenium addition primarily explain in this contact example?
Atomic identity, reference properties and structure models
INTERACTIVE 3D44 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Kr] 4d7 5s1. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
Ruthenium emerged from the difficult chemistry of platinum-bearing residues. An earlier claim for a substance called vestium was withdrawn when others could not confirm it. Karl Klaus established ruthenium in 1844 and named it after Ruthenia, a Latin name associated with Russia. The distinction matters: a suggestive observation and a reproducible elemental identification are different steps, even when later accounts join them into one story.
1808
Vestium claim
An early claim associated with platinum residues was subsequently withdrawn.
1844
Ruthenium established
Karl Klaus established the new platinum-group element.
Ruthenium occurs with other platinum-group metals and can be recovered through processing associated with nickel . Its companions are central to its supply: a must separate several chemically related metals from a complex feed. The element is therefore often encountered first as part of a mixture.
Ruthenium is a hard platinum-group metal, but its applications extend beyond metallic hardness. Ruthenium-containing compounds also participate in . The metal, an containing it, and an coating are distinct materials. Their different chemical environments explain why the same element can contribute to wear resistance and reaction control.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
solid
293.15 K, 101.325 kPa
Melting point in K
2607 K
at standard pressure unless noted
Boiling point in K
4423 K
101.325 kPa
Density in g/cm³
12.45 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
2.2 Pauling
Pauling scale
First ionization energy in kJ/mol
710.2 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
146 pm
single-bond covalent radius
Common oxidation states
+3, +4
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
0.001 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1844 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 5
Ru 2.2 Pauling · Ruthenium
Electronegativity across period 5. Exact values.
Rb
0.82
Sr
0.95
Y
1.22
Zr
1.33
Nb
1.6
Mo
2.16
Tc
1.9
Ru
2.2
Rh
2.28
Pd
2.2
Ag
1.93
Cd
1.69
In
1.78
Sn
1.96
Sb
2.05
Te
2.1
I
2.66
Xe
2.6
Electronegativity down group 8
Ru 2.2 Pauling · Ruthenium
Electronegativity down group 8. Exact values.
Fe
1.83
Ru
2.2
Os
2.2
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
