Ruthenium (Ru)
“The platinum-family metal hiding in every computer hard drive — and whose catalyst earned chemistry’s 2005 Nobel Prize.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
The notes
Characteristics
- Electron configuration [Kr] 4d⁷ 5s¹ — a genuine aufbau exception; Period 5, Group 8 transition metal of the platinum group.
- Melts at 2,334 °C and shrugs off aqua regia, the acid mixture that dissolves gold; only molten alkalis with oxidisers attack it.
- Shows oxidation states all the way to +8 — the volatile, fiercely oxidising ruthenium tetroxide RuO₄ is one of very few +8 compounds in chemistry.
- A superb catalyst: Grubbs’s ruthenium catalyst for olefin metathesis won the 2005 Nobel Prize in Chemistry.
A hard, brittle, silvery-white metal of the platinum family with a rather subdued lustre. It is so hard that a hammer blow shatters it instead of bending it, and almost no one ever sees it as anything but a powder or a thin coating.
Where you meet it
✦ Uses
- Ultrathin ruthenium layers inside hard disk drives keep magnetic bits stacked upright — every laptop and external HDD relies on them.
- RuO₂-coated electrodes for factory chlorine production from brine — the chlorine behind water treatment and bleach.
- Grubbs-type catalysts for building fine chemicals, pharmaceuticals and advanced plastics.
- Platinum-ruthenium alloys for long-life electrical contacts, fountain-pen nib tips and aircraft spark plugs.
◍ Everyday examples
- The hard drive inside a school or office computer — its dense storage would be impossible without ruthenium interlayers.
- The chlorine that treats drinking water and keeps swimming pools clean is often made using ruthenium-coated electrodes.
- A quality fountain pen’s iridium-tipped nib usually contains ruthenium in the alloy ball at its point.
History & name
In 1828 the Baltic German chemist Gottfried Osann examined the black residue left after dissolving crude Ural platinum and reported three new metals, one of which he named ruthenium. Other chemists could not repeat his results, and the claim was abandoned. Sixteen years later, in 1844, Karl Ernst Claus of Kazan University re-examined the same residues, isolated the genuine new metal in reasonable purity, and honourably revived Osann’s name — Ruthenia, the scholarly Latin name for the old land of Rus’, honouring his Russian homeland.