from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A very hard, heavy, gray metallic element that is exceptionally resistant to chemical attack below 150°C. It is used to make light-bulb filaments, electrolytic capacitors, lightning arresters, nuclear reactor parts, and some surgical instruments. 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 Table at element.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A metallic chemical element (symbol Ta) with an atomic number of 73.
from the GNU version of the Collaborative International Dictionary of English
- n. A rare nonmetallic element found in certain minerals, as tantalite, samarskite, and fergusonite, and isolated as a dark powder which becomes steel-gray by burnishing. Symbol Ta. Atomic weight 182.0. Formerly called also tantalium.
from The Century Dictionary and Cyclopedia
- n. Knowledge of this metal has been much increased by recent research. Brought to the elementary state by heating together sodium and an alkaline tantalofluoride and fused in an electric furnace, it appears as a solid of grayish-white color and metallic luster, like platinum, of specific gravity 16.64. It combines in a most remarkable way intense hardness with a high degree of ductility, so that it can be drawn into wire.05 millimeters in diameter having a resisting tensile stress ranging up to 93 kilos., or for fine wire 150 or 160 kilos., per square millimeter before breaking. It melts at 2,250–2,300° C., resists all the ordinary acids and alkaline solutions, is attacked by hydrofluoric acid and by fused caustic alkalis, and as thin wire bums, when heated in oxygen, with a bright white light.
- n. Chemical symbol, Ta; atomic weight, 192. One of the rare metals occurring in various combinations, but hardly known at all in the separate metallic state.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a hard grey lustrous metallic element that is highly resistant to corrosion; occurs in niobite and fergusonite and tantalite
After processing, coltan turns into a powder called tantalum, which is used extensively in a wealth of western electronic devices including cell phones, computers and, of course, game consoles.
He also found that Iran was acquiring a rare metal called tantalum, "used in those roadside bombs that are being used against our troops in Iraq and Afghanistan."
Later, they would plug the holes with “buttons” made of a rare metal called tantalum.
It's called tantalum and, according to the WSJ, is "used in parts such as capacitors, which store electric charges, and help power most smartphones and other devices."
Chavez, speaking today on state television, said Venezuela can't allow illegal miners to continue exploiting deposits rich in gold and coltan, an ore containing tantalum, which is used in mobile phones and video-game consoles.
That's the image that activists have used to scare U.S. tech companies into getting off of what they call "conflict minerals," namely tantalum, tin, gold and tungsten sourced from mines in the Democratic Republic of Congo, and surrounding regions, that are, in many cases, controlled by armed militia.
Mining tantalum, which is used for cell phones, is a surface activity that can spread out and cause a big impact.
Trade in tantalum, which is used to store electricity in capacitors in iPods, digital cameras, and cell phones earns the armed groups an estimated 8 million dollars annually.
The company is taking actions to ensure that minerals such as tantalum, tin, tungsten and gold are not purchased from smelters that get their products from regions where armed conflict or human-rights abuses are known to be occurring, according to the report.
Some suppliers say prices could increase if there is an increase in raw materials such as tantalum ore.