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microelectronics

(Encyclopedia)microelectronics, branch of electronic technology devoted to the design and development of extremely small electronic devices that consume very little electric power. Although the term is sometimes us...

methane

(Encyclopedia)methane mĕthˈān [key], CH4, colorless, odorless, gaseous saturated hydrocarbon; the simplest alkane. It is less dense than air, melts at −184℃, and boils at −161.4℃. It is combustible and c...

Pará, state, Brazil

(Encyclopedia)Pará pəräˈ [key], state (1996 pop. 5,552,783), 474,896 sq mi (1,229,981 sq km), N Brazil, in the lower Amazon River basin bordering on the Guianas and the Atlantic Ocean. Belém is the capital. Mo...

oxide

(Encyclopedia)oxide, chemical compound containing oxygen and one other chemical element. Oxides are widely and abundantly distributed in nature. Water is the oxide of hydrogen. Silicon dioxide is the major componen...

Washington Monument

(Encyclopedia)Washington Monument, obelisk-shaped tower, 555 ft 51⁄9 in. (169.3 m) high, located on a 106-acre (43-hectare) site at the west end of the Mall, Washington, D.C.; dedicated 1885. The world's tallest ...

clay

(Encyclopedia)clay, common name for a number of fine-grained, earthy materials that become plastic when wet. Chemically, clays are hydrous aluminum silicates, ordinarily containing impurities, e.g., potassium, sodi...

potassium

(Encyclopedia)potassium pətăsˈēəm [key], a metallic chemical element; symbol K [Lat. kalium=alkali]; at. no. 19; at. wt. 39.0983; m.p. 63.25℃; b.p. 760℃; sp. gr. .862 at 20℃; valence +1. Potassium is a s...

Dar es Salaam

(Encyclopedia)Dar es Salaam därˈ-ĕs-sälämˈ [key] [Arab.,=haven of peace], city (2021 est. metro area pop. ...

hydroxide

(Encyclopedia)hydroxide hīdrŏkˈsīd [key], chemical compound that contains the hydroxyl (−OH) radical. The term refers especially to inorganic compounds. Organic compounds that have the hydroxyl radical as a f...

Henan

(Encyclopedia)Henan or Honan both: ho͝oˈnänˈ [key], province, c.65,000 sq mi (168,350 sq km), NE China. The capital is ...