78PtPlatinum195.0849[Xe] 4f¹⁴ 5d⁹ 6s¹
transition metal

Platinum

Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, gray-white transition metal. Its name is derived from the Spanish term platina, which is literally translated into "little silver".

Electronic structure

A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.

Electrons by shell
Electron configuration
4f14
5d9
6s1

54 is the [Xe] core total across five shells.

Properties

At a glance

Atomic number
78
Atomic mass
195.0849 u
Phase
Solid
Density
21.45 g/cm³
Melting point
2,041.4 K
Boiling point
4,098 K
First ionization energy
870 kJ/mol
Electronegativity
2.28
Electron affinity
205.041 kJ/mol
Molar heat capacity
25.86 J/(mol·K)
Period
6
Appearance
silvery white

Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.

Keep exploring

Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.