Platinum (Pt)

Platinum (Pt) is element 78, a transition metal. Atomic mass 195.084, configuration [Xe] 4f¹⁴ 5d⁹ 6s¹. Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.

Open Platinum in the interactive periodic table

Key facts

Atomic number78
SymbolPt
Standard atomic weight195.084(9)
CategoryTransition Metal
Group10
Period6
State at room temperatureSolid
Electron configuration[Xe] 4f¹⁴ 5d⁹ 6s¹
Valence electrons1 (Variable)
Common oxidation states+2, +4
Common ionsNo common ions
Electronegativity (Pauling)2.2
First ionization energy870 kJ/mol
Electron affinity205.3 kJ/mol
Atomic radius135 pm
Density21.5 g/cm³
Melting point1768.8°C
Boiling point3825°C
Specific heat0.133 J/(g·°C)

Natural isotopes

Common uses

Where it matters

Hazards

History

Discovered1735
Discovered byAntonio de Ulloa
NameFrom Spanish platina (little silver)