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Cobalt | |
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State | Ontario |
Country | Canada |
Capital | |
Population | 1128 |
Cobalt is a chemical element with the symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was later thought to be due to the known metal bismuth. Miners had long used the name kobold ore (German for goblin ore) for some of the blue-pigment-producing minerals; they were so named because they were poor in known metals, and gave poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the kobold.
Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). The element is, however, more usually produced as a by-product of copper and nickel mining.
Manaus | |
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State | |
Country | |
Capital | |
Population | 0 |
Manaus (; Portuguese: [mɐˈnaws, mɐˈnawʃ, maˈnaws]) is the capital and largest city of the Brazilian state of Amazonas. It is the seventh-largest city in Brazil, with an estimated 2019 population of 2,182,763 distributed over a land area of about 11,401 km2 (4,402 sq mi). Located at the east center of the state, the city is the center of the Manaus metropolitan area and the largest metropolitan area in the North Region of Brazil by urban landmass. It is situated near the confluence of the Negro and Solimões rivers.
The city was founded in 1669 as the Fort of São José do Rio Negro. It was elevated to a town in 1832 with the name of "Manaus", an altered spelling of the indigenous Manaós peoples, and legally transformed into a city on October 24, 1848, with the name of Cidade da Barra do Rio Negro, Portuguese for "The City of the Margins of the Black River". On September 4, 1856 it returned to its original name.Manaus is located in the center of the world's largest rainforest, and home to the National Institute of Amazonian Research, being the most important center for scientific studies in the Amazon region and for international sustainability issues. It was known at the beginning of the century, as "Heart of the Amazon" and "City of the Forest".