Platinum (Pt)

Attractive greyish-white metal. When pure, it is malleable and ductile. Does not oxidize in air, insoluble in hydrochloric and nitric acid. Corroded by halogens, cyandies, sulphur and alkalis. Hydrogen and Oxygen react explosively in the presence of platinumpy. There are six stable isotopes and three radioisotopes, the most stable being Pt-193 with a half-life of 60 years. Platinum is used in jewelry, laboratory equipment, electrical contacts, dentistry, and anti-pollution devices in cars. PtCl2(NH3)2 is used to treat some forms of cancer. Platinum-Cobalt alloys have magnetic properties. It is also used in the definition of the Standard Hydrogen Electrode. Discovered by Antonio de Ulloa in South America in 1735. The name comes from the Spanish word platina which means silver. Platinum metal is generally not a health concern due to its unreactivity, however platinum compounds should be considered highly toxic.
Atomic Number78
Atomic Weight195.084
Mass Number195
Protons78 p+
Neutrons117 n0
Electrons78 e-
Platinum crystals.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram


Atomic Radius
135 pm
Atomic Volume
Covalent Radius
123 pm
Metallic Radius
130 pm
Ionic Radius
60 pm
Crystal Radius
74 pm
Van der Waals radius
213 pm
21.5 g/cm³
Boiling Point
4,100 K
Melting Point
2,045 K
Electrons per shell2, 8, 18, 32, 17, 1
2.2493203506913 eV/particle
Proton Affinity
Electron Affinity
Ionization Potential
8.95883 eV/particle
Heat of Vaporization
470 kJ/mol
Heat of Fusion
21.76 kJ/mol
Heat of Formation
565.7 kJ/mol
Molar Heat Capacity
25.86 J/(mol K)
Specific Heat Capacity
0.133 J/(g⋅K)
Thermal Conductivity
71.6 W/(m K)
Gas Basicity
Dipole Polarizability
48 a₀
C6 Dispersion Coefficient
Oxidation States2, 4, 5, 6
Crystal StructureFace Centered Cubic (FCC)
Lattice Constant
3.92 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Xe] 4f14 5d9 6s1
Magnetic Ordering
Magnetic Susceptibility
Poisson Ratio
Shear Modulus
Young's Modulus
Alternate Names
Adiabatic Index
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Magnetic Susceptibility
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
CategoryTransition metals, Transition metals
Glawe Number64
Mendeleev Number69
Pettifor Number68
Geochemical Classnoble metal
Goldschmidt Classsiderophile
Decay Mode
Abundance in Earth's crust
0.005 mg/kg
Abundance in Oceans
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe5×10-7%

Isotopes of Platinum

Stable Isotopes
190Pt 192Pt 194Pt 195Pt 196Pt 198Pt
Unstable Isotopes
166Pt 167Pt 168Pt 169Pt 170Pt 171Pt 172Pt 173Pt 174Pt 175Pt 176Pt 177Pt 178Pt 179Pt 180Pt 181Pt 182Pt 183Pt 184Pt 185Pt 186Pt 187Pt 188Pt 189Pt 191Pt 193Pt 197Pt 199Pt 200Pt 201Pt 202Pt


Platinum was first used by pre-Columbian South American natives to produce artifacts. Antonio de Ulloa published his findings about platinum in 1748, but Sir Charles Wood also investigated the metal in 1741. First reference to it as a new metal was made by William Brownrigg in 1750. From the Spanish word platina, meaning silver

DiscoverersJulius Scaliger
Discovery LocationItaly
Discovery Year1735
Name OriginSpanish: platina (little silver).
Platinum is considered to be non-toxic
Platinum exists in higher abundances on the Moon and in meteorites


The most common use of platinum is as a catalyst in chemical reactions. Platinum is used in jewelry, decoration and dental work. Platinum-cobalt, an alloy of roughly three parts platinum and one part cobalt, is used to make relatively strong permanent magnets. Platinum-based anodes are used in ships, pipelines, and steel piers. Used in jewelry, to make crucible and special containers and as a catalyst. Used with cobalt to produce very strong magnets. Also to make standard weights and measures. Resists corrosion and acid attacks except aqua regia.


Produced from deposits of native, or elemental, platinum.