78PtPlatinumtransition metal
Atomic weight195.084conventional

Platinum(Pt)

Platinum (Pt) is a transition metal in period 6 of the periodic table. Its properties reflect its electron configuration and position among neighbouring elements.

transition metalGroup 10Period 6d-blocksolid at STP
Position:Period 6, Group 10, Block d• Grid6:10[Xe] 4f¹⁴ 5d⁹ 6s¹

KEY PROPERTIES

Atomic number
78
Atomic weight
195.084
Category / Block
transition metal • d-block
Group / Period
10 / 6
Electron configuration
[Xe] 4f¹⁴ 5d⁹ 6s¹
State at STP
solid(STP (0 °C, 100 kPa))

Electron configuration & shells

[Xe] 4f¹⁴ 5d⁹ 6s¹

281832171

Shell model is schematic — see lesson on atomic structure for orbitals. Oxidation states: +2, +4. Common ions: Pt²⁺, Pt⁴⁺.

Measured properties

Values at stated conditions; missing data shown as “—”. Radii distinguished by type; densities at stated phase/temperature.

Electronegativity (Pauling)
2.28
First ionization energy
870 kJ·mol⁻¹ (first ionization, gas phase)
Atomic radius
136 pm (calculated)
Covalent radius
136 pm (covalent)
Van der Waals radius
175 pm (van der Waals)
Density
21.46 g·cm⁻³ (solid at 20 °C, 1 atm)
Melting point
2041.4 K (1 atm)
Boiling point
4098 K (1 atm)

Standard conditions: 1 atm unless noted. Values with null are not established or not comparable across allotropes. Radii are distinguished by type. Densities at stated phase/temperature.

Isotopes — Platinum
Mass numberAbundanceStabilityHalf-life
195trace/syntheticstable

Isotopic abundances are natural terrestrial values where applicable; synthetic isotopes shown as trace.

Occurrence & uses

Occurs naturally; abundance and extraction depend on geochemistry. For heavy synthetics (Z > 92), no natural occurrence.

  • Industrial use
  • Laboratory reagent
  • Research

Discovery

Unknown — —

Safety

Consult SDS for compounds of this element; elemental hazards depend on form and exposure. This entry summarises the element, not every compound.

SOURCES

  1. [nist-atomic-weights]nist-atomic-weights (2022)/#nist-atomic-weights
  2. [nist-2022]nist-2022 (2022)/#nist-2022
  3. [iupac-gold]iupac-gold (2022)/#iupac-gold

Last reviewed: 2026-08-22 • Reviewer: dr-example

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