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Transition metals

Platinum

A precious, unreactive metal central to catalysis and jewelry.

Atomic #78Mass195.08Blockd-blockPeriod6Group10
Pt78 · 195.08
3D Atom Explorer

Inside the Platinum 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 Platinum atom step by step.

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Electron configuration

[Xe] 4f14 5d9 6s1

A neutral Platinum atom has 78 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 432 e⁻Shell 517 e⁻Shell 61 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
2041 K (1768 °C)
Boiling point
4098 K (3825 °C)
Density
21.46 g/cm³
Electronegativity
2.28 Pauling
Atomic radius
135 pm
1st ionization energy
870 kJ/mol
Category
Transition metals
History

Discovery & naming

Discovered
1735
Discovered by
Antonio de Ulloa
Origin of name
Spanish 'platina', meaning little silver.

Notable uses

Catalytic converters, jewellery, and lab equipment.

Cosmic origin

Where Platinum comes from

Neutron star mergers

Neutron star mergers are considered a major source. Some supernova environments may contribute as well.

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

Summary

Atomic number
78
Atomic mass
195.08
Category
Transition metals
Group · Period
10 · 6
Block
d-block
Shells
2 · 8 · 18 · 32 · 17 · 1