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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...

platinum

(Encyclopedia)platinum plătˈənəm [key], metallic chemical element; symbol Pt; at. no. 78; at. wt. 195.084; m.p. 1,772℃; b.p. 3,827±100℃; sp. gr. 21.45 at 20℃; valence +2 or +4. Pure platinum is a malleab...

Mississippi, river, United States

(Encyclopedia)Mississippi, river, principal river of the United States, c.2,350 mi (3,780 km) long, exceeded in length only by the Missouri, the chief of its numerous tributaries. The combined Missouri-Mississippi ...

Ghana, country, Africa

(Encyclopedia)CE5 Ghana, officially Republic of Ghana, republic (2015 est. pop. 27,583,000), 92,099 sq mi (238,536 sq km), W Africa, on the Gulf of Guinea, an arm of the Atlantic Ocean. The capital and largest c...

Equatorial Guinea

(Encyclopedia)CE5 Equatorial Guinea gĭnˈē [key], officially Republic of Equatorial Guinea, republic (2021 est. pop. ...

Nigeria

(Encyclopedia)CE5 Nigeria nījĭrˈēə [key], officially Federal Republic of Nigeria, republic (2015 est. pop. 181,182,000), 356,667 sq mi (923,768 sq km), W Africa. It borders on the Gulf of Guinea (an arm of ...

Arabs

(Encyclopedia)Arabs, name originally applied to the Semitic peoples of the Arabian Peninsula. It now refers to those persons whose primary language is Arabic. They constitute most of the population of Algeria, Bahr...

Tuscany

(Encyclopedia)Tuscany tŭsˈkənē [key], Ital. Toscana, region (1991 pop. 3,538,619), 8,876 sq mi (22,989 sq km), N central Italy, bordering on the Tyrrhenian Sea in the west and including the Tuscan Archipelago. ...

Tennessee Valley Authority

(Encyclopedia)Tennessee Valley Authority (TVA), independent U.S. government corporate agency, created in 1933 by act of Congress; it is responsible for the integrated development of the Tennessee River basin. The h...

Gabon

(Encyclopedia)CE5 Gabon gäbôNˈ [key], officially Gabonese Republic, republic (2015 est. pop. 1,930,000), 103,346 sq mi (267,667 sq km), W central Africa. It borders on the Atlantic Ocean in the west, on Equat...