|1.||a ductile malleable silvery-white metallic element, very resistant to heat and chemicals. It occurs free and in association with other platinum metals, esp in osmiridium: used in jewellery, laboratory apparatus, electrical contacts, dentistry, electroplating, and as a catalyst. Symbol: Pt; atomic no: 78; atomic wt: 195.08; valency: 1--4; relative density: 21.45; melting pt: 1769°C; boiling pt: 3827±100°C|
|2.||a. a medium to light grey colour|
|b. (as adjective): a platinum carpet|
|[C19: New Latin, from |
platinum plat·i·num (plāt'n-əm)
A ductile malleable metallic element usually occurring mixed with other metals such as iridium, osmium, or nickel and used as a catalyst and in dentistry. Atomic number 78; atomic weight 195.08; melting point 1,768°C; boiling point 3,825°C; specific gravity 21.45; valence 2, 3, 4.
|platinum (plāt'n-əm) Pronunciation Key
A soft, ductile, malleable, silver-white metallic element that usually occurs with osmium, iridium, palladium, or nickel. It has a high melting point and does not corrode in air. Platinum is used as a catalyst and in making jewelry, electrical contacts, and dental crowns. Atomic number 78; atomic weight 195.08; melting point 1,772°C; boiling point 3,827°C; specific gravity 21.45; valence 2, 3, 4. See Periodic Table.