Platinum

platino

Spanish explorers first found platinum in the mines of South America in the 1700s. They obtained a whitish substance that locals living nearby called platina, meaning "little silver". This precious metal has a silvery-white luster. Platinum rarely reacts with other elements, even at high temperatures. This makes it difficult to extract its ores, such as esperrylite. Pure platinum does not corrode or tarnish. However, it is not easy to shape, so the use of platinum was limited to jewelry and watch making. By the 20th century, more applications were discovered. Platinum can be used instead of silver to generate photographic prints, and instead of gold to make dental fillings. Today, platinum plays an important role in several technologies. For example, it is used in fuel cells, devices that generate electricity by combining hydrogen and oxygen. These cells do not need to be recharged like other batteries. Cancer drugs, such as cisplatin, contain this element. In addition, stents made of pure platinum help repair damaged blood vessels.

Summary of properties (Pt)

Atomic weight195.084(9)
Discoverer (year)Scaliger, Julius (1735)
Natural formmetallic solid (face centered cubic)
Electron configuration[Xe] 414 5d9 6s1
Melting point (ºC)1772
Boiling point (ºC)3827
Abundance in earth's crust (ppm)0.005
Isotope (abundance)190Pt (0.014), 192Pt (0.782), 194Pt (32.967), 195Pt (33.832), 196Pt (25.242), 198Pt (7.163)
Density g/cm321.45
Van der Waals radius (pm)213
Covalent radius (pm)130
Electronegativity (Pauling)2.28
Vaporization enthalpy (kJ/mol)510.50
Enthalpy of fusion (kJ/mol)22.17
Specific heat capacity (J/g·K) at 25ºC and 1 atm0.13
Thermal conductivity (W/cm·K) at 25ºC and 1 atm0.720
Oxidation state+4, +2
Electron affinity (eV)2.13
1st Ionization potential (eV)8.9588

Back to the Periodic Table of the Elements.