palladium(redirected from Palladíum)
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n. Symbol Pd
A soft, ductile, lustrous gray-white, tarnish-resistant, metallic element occurring naturally with platinum, especially in gold, nickel, and copper ores. Because it can absorb large amounts of hydrogen, it is used as a purification filter for hydrogen and a catalyst in hydrogenation. It is alloyed for use in electric contacts, jewelry, nonmagnetic watch parts, and surgical instruments. Atomic number 46; atomic weight 106.4; melting point 1,554.8°C; boiling point 2,963°C; specific gravity 12.02 (20°C); valence 2, 3, 4. See Periodic Table.
[From Pallas (discovered at the same time as the element).]
n. pl. pal·la·di·a (-dē-ə) or pal·la·di·ums
1. A safeguard, especially one viewed as a guarantee of the integrity of social institutions: the Bill of Rights, palladium of American civil liberties.
2. A sacred object that was believed to have the power to preserve a city or state possessing it.
[Middle English Palladion, a statue of Pallas Athena believed to protect Troy, from Old French palladion, from Latin Palladium, from Greek Palladion, from Pallas, Pallad-, Pallas Athena.]
(Elements & Compounds) a ductile malleable silvery-white element of the platinum metal group occurring principally in nickel-bearing ores: used as a hydrogenation catalyst and, alloyed with gold, in jewellery. Symbol: Pd; atomic no: 46; atomic wt: 106.42; valency: 2, 3, or 4; relative density: 1202; melting pt: 1555°C; boiling pt: 2964°C
[C19: named after the asteroid Pallas, at the time (1803) a recent discovery]
something believed to ensure protection; safeguard
[C17: after the Palladium]
(Classical Myth & Legend) a statue of Pallas Athena, esp the one upon which the safety of Troy depended
pal•la•di•um(pəˈleɪ di əm)
a rare silver-white ductile metallic element of the platinum group, used chiefly as a catalyst and in dental and other alloys. Symbol: Pd; at. wt.: 106.4; at. no.: 46; sp. gr.: 12 at 20°C.
pal•lad′ic (-ˈlæd ɪk) pal•la′dous (pəˈleɪ dəs, ˈpæl ə dəs) adj.
Pal•la•di•um(pəˈleɪ di əm)
n., pl. -di•a (-di ə)
1. a statue of Athena, esp. one on the citadel of Troy on which the safety of the city was supposed to depend.
2. (usu. l.c.) anything believed to provide protection or safety; safeguard.
[< Latin Palladium < Greek Palládion, n. use of neuter of Palládios of Pallas, derivative of Pallás, s. Pallad- Pallas]
Symbol Pd An easily shaped, grayish-white metallic element that occurs naturally with platinum. Because it can absorb large amounts of hydrogen, it is used as a catalyst in reactions involving hydrogen. Palladium and its alloys are used to make electrical contacts and jewelry. Atomic number 46. See Periodic Table.
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|Noun||1.||palladium - a silver-white metallic element of the platinum group that resembles platinum; occurs in some copper and nickel ores; does not tarnish at ordinary temperatures and is used (alloyed with gold) in jewelry|
palladium[pəˈleɪdɪəm] N → paladio m
n (Chem) → Palladium nt