Platinum
Definition and meaning of Platinum in chemistry.
Platinum is a chemical element with the symbol Pt and atomic number 78, widely recognized as a dense, malleable, and highly unreactive precious metal. This silvery-white transition metal is the namesake of the platinum group and is highly valued for its exceptional catalytic properties and resistance to corrosion.
In more detail
Situated in group 10 of the periodic table, platinum is a noble metal that demonstrates remarkable chemical stability, remaining unoxidized in air even at extreme temperatures and resisting attack by most common acids, although it will dissolve in hot aqua regia. It occurs naturally in the uncombined state as native platinum, often found in alluvial sands and primary magmatic ore deposits alongside other platinum-group metals, nickel, and copper. Platinum exhibits excellent ductility and malleability, allowing it to be drawn into fine wires or hammered into thin sheets without losing its structural integrity. Chemically, its most common oxidation states are +2 and +4, which allow it to form numerous stable coordination complexes, some of which possess significant biological and medicinal activity. The ability of platinum surfaces to adsorb hydrogen and oxygen gases rapidly at room temperature makes it an indispensable catalyst in various industrial chemical reactions, including petroleum refining and the synthesis of nitric acid.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Pt |
| Atomic number | 78 |
| Atomic mass | 195.08 u |
| Category | Transition Metal |
| State at room temperature | Solid |
| Melting point | 1768 degrees Celsius |
| Magnetic ordering | Paramagnetic |
The largest application of platinum is in the production of automotive catalytic converters, where it facilitates the complete combustion of unburned hydrocarbons and carbon monoxide into carbon dioxide and water vapor.
Frequently asked questions
Why is platinum considered a noble metal?
Platinum is classified as a noble metal because it exhibits outstanding resistance to chemical attack and oxidation, maintaining its metallic luster and structural integrity even in harsh, corrosive environments.
How is platinum used in medicine?
Certain platinum-based coordination complexes, notably cisplatin, are highly effective chemotherapeutic agents used to treat various cancers by binding to and cross-linking cellular DNA, which ultimately triggers cell death.