|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|a hard greyish-white metallic element that occurs with niobium in tantalite and columbite: used in electrical capacitors in most circuit boards and in alloys to increase hardness and chemical resistance, esp in surgical instruments. Symbol: Ta; atomic no: 73; atomic wt: 180.9479; valency: 2, 3, 4, or 5; relative density: 16.654; melting pt: 3020°C; boiling pt: 5458±100°C|
|[C19: named after |
tantalum tan·ta·lum (tān'tə-ləm)
A hard heavy metallic element that is exceptionally resistant to chemical attack below 150°C and is used to make electronic components and surgical instruments. Atomic number 73; atomic weight 180.948; melting point 3,017°C; boiling point 5,458°C; specific gravity 16.7; valence 2, 3, 4, 5.
|tantalum (tān'tə-ləm) Pronunciation Key
A hard, heavy, gray metallic element that is highly resistant to corrosion at low temperatures. It is used to make light-bulb filaments, surgical instruments, and glass for camera lenses. Atomic number 73; atomic weight 180.948; melting point 2,996°C; boiling point 5,425°C; specific gravity 16.6; valence 2, 3, 4, 5. See Periodic Table.