pal·la·di·um /pəˈlediəm/
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pal·la·di·um /pəˈledɪəm/ 名詞
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Pal·la·di·um n.
1. Gr. Antiq. Any statue of the goddess Pallas; esp., the famous statue on the preservation of which depended the safety of ancient Troy.
2. Hence: That which affords effectual protection or security; a safeguard; as, the trial by jury is the palladium of our civil rights.
Pal·la·di·um, n. Chem. A rare metallic element of the light platinum group, found native, and also alloyed with platinum and gold. It is a silver-white metal resembling platinum, and like it permanent and untarnished in the air, but is more easily fusible, with a melting point of 1555° C. It can also be prepared as a finely divided black powder. It is unique in its power of absorbing hydrogen, which it does to the extent of nearly a thousand volumes, forming the alloy Pd2H. It is used for graduated circles and verniers, for plating certain silver goods, and somewhat in dentistry. It was so named in 1804 by Wollaston from the asteroid Pallas, which was discovered in 1802. Symbol Pd. Atomic number, 46. Atomic weight, 106.42. Density 12.0.
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palladium
n : 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 [syn: Pd, atomic
number 46]
palladium
Symbol: Pd
Atomic number: 46
Atomic weight: 106.4
Soft white ductile transition element. Found with some copper and nickel
ores. Does not react with oxygen at normal temperatures. Dissolves slowly
in hydrochloric acid. Discovered in 1803 by W.H. Wollaston.