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Transition metals

Ruthenium

A hard platinum-group metal used in electronics and catalysis.

Atomic #44Mass101.07Blockd-blockPeriod5Group8
Ru44 · 101.07
3D Atom Explorer

Inside the Ruthenium atom

Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Ruthenium atom step by step.

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Electron configuration

[Kr] 4d7 5s1

A neutral Ruthenium atom has 44 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.

Shell distribution

Shell 12 e⁻Shell 28 e⁻Shell 318 e⁻Shell 415 e⁻Shell 51 e⁻

Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.

Properties

Physical & atomic properties

State (room temp)
Solid
Melting point
2607 K (2334 °C)
Boiling point
4423 K (4150 °C)
Density
12.37 g/cm³
Electronegativity
2.2 Pauling
Atomic radius
130 pm
1st ionization energy
710 kJ/mol
Category
Transition metals
History

Discovery & naming

Discovered
1844
Discovered by
Karl Ernst Claus
Origin of name
Latin 'Ruthenia', for Russia.

Notable uses

Wear-resistant electrical contacts and catalysts.

Cosmic origin

Where Ruthenium comes from

Several comparable sources

Both slow neutron capture in dying stars and rapid capture in explosive events contribute meaningfully.

Simplified origin map — many elements form through more than one astrophysical pathway.

Summary

Atomic number
44
Atomic mass
101.07
Category
Transition metals
Group · Period
8 · 5
Block
d-block
Shells
2 · 8 · 18 · 15 · 1