- A metallic element, atomic no. 78, atomic wt. 195.08, used for making small parts for chemical apparatus because of its resistance to acids; in powdered form (p. black), it is an important catalyst in hydrogenation. Some of its salts have been used in the treatment of syphilis. A derivative, cisplatin, is used as an antineoplastic agent. [Mod. L., originally platina, fr. Sp. plata, silver]
* * *plat·i·num 'plat-nəm, -ən-əm n a heavy precious grayish white noncorroding ductile malleable metallic element that fuses with difficulty and is used esp. in chemical ware and apparatus, as a catalyst, and in dental and jewelry alloys symbol Pt see ELEMENT (table)
* * *plat·i·num (Pt) (platґĭ-nəm) [L.] a heavy, soft, whitish metal, resembling tin: atomic number, 78; atomic weight, 195.09; specific gravity, 21.37. It also occurs as a black powder (p. black) and a spongy substance (spongy p.). Metallic platinum is insoluble except in nitrohydrochloric acid, and is fusible only at very high temperatures; it is therefore used in the manufacture of chemical apparatus. Platinum black and spongy platinum have a strong affinity for oxygen, and act as powerful oxidizing and catalytic agents.
Medical dictionary. 2011.