Uses of Platinum
The first known reference to platinum can be found in the writings of Italian physician, scholar, and poet Julius Caesar Scaliger (1484-1558). Scaliger apparently saw platinum while visiting Central America in 1557. He referred to a hard metal that the natives had learned to work with, but the Spanish had not. The metal had been called platina ("little silver") by the natives. The name was given to the material because it got in the way of mining silver and gold . Since the natives knew of no use for the platina, they thought of it as a nuisance.
The first complete description of platinum was given by the Spanish military leader Don Antonio de Ulloa (1716-95). While serving in South America from 1735 to 1746, de Ulloa collected samples of platinum. He later wrote a report about the metal, describing how it was mined and used. De Ulloa is often given credit for discovering platinum on the basis of the report he wrote.
Reports of the new element spread through Europe. Scientists were fascinated by its physical properties. It was not only beautiful to look at, but resistant to corrosion (rusting). Many people saw that it could be used in jewelry and art objects, as with gold and silver. Demand for the metal began to grow, leading to what was then called the "Platinum Age in Spain."
Platinum is a silver-gray, shiny metal that is both malleable and ductile. Malleable means capable of being hammered into thin sheets. Platinum can be hammered into a fine sheet no more than 100 atoms thick, thinner than aluminum foil.
Ductile means the metal can be drawn into thin wires. Platinum has a melting point of about 1,773°C (3,223°F) and a boiling point of about 3,827°C (6,921°F). Its density is 21.45 grams per cubic centimeter, making it one of the densest elements.
Platinum is a relatively inactive metal. When exposed to air, it does not tarnish or corrode. It is not attacked by most acids, but will dissolve in aqua regia. Aqua regia is a mixture of hydrochloric and nitric acids. It often reacts with materials that do not react with either acid separately. Platinum also dissolves in very hot alkalis. An alkali is a chemical with properties opposite those of an acid. Sodium hydroxide ("common lye") and limewater are examples of alkalis.
An unusual property of platinum is that it will absorb large quantities of hydrogen gas at high temperatures. The platinum soaks up hydrogen the way a sponge soaks up water.