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.
Manchester | |
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State | |
Country | |
Capital | |
Population | 0 |
Manchester () is a city and metropolitan borough in Greater Manchester, England. The city has a population of 547,627 (as of 2018) and lies within the United Kingdom's second-most populous urban area, with a population of 2.7 million and second-most populous metropolitan area, with a population of 3.3 million. It is fringed by the Cheshire Plain to the south, the Pennines to the north and east, and an arc of towns with which it forms a continuous conurbation. The local authority for the city is Manchester City Council.
The recorded history of Manchester began with the civilian settlement associated with the Roman fort of Mamucium or Mancunium, which was established in about AD 79 on a sandstone bluff near the confluence of the rivers Medlock and Irwell. Although historically and traditionally a part of Lancashire, areas of Cheshire south of the River Mersey were incorporated into Manchester in the 20th century. The first to be included, Wythenshawe, was added to the city in 1931. Throughout the Middle Ages Manchester remained a manorial township, but began to expand "at an astonishing rate" around the turn of the 19th century. Manchester's unplanned urbanisation was brought on by a boom in textile manufacture during the Industrial Revolution, and resulted in it becoming the world's first industrialised city.