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Denver | |
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State | Nova Scotia |
Country | Canada |
Capital | |
Population | 0 |
Denver (), officially the City and County of Denver, is the capital and most populous municipality of the U.S. state of Colorado. Denver is located in the South Platte River Valley on the western edge of the High Plains just east of the Front Range of the Rocky Mountains. With an estimated population of 727,211 in 2019, Denver is the 19th-most populous city in the United States, the fifth-most populous state capital, and the most populous city located in the Mountain states. The metropolitan area surrounding Denver represents a majority of the population and economic activity in the Front Range region, the area where an estimated 85% of Colorado's population lives. The Denver downtown district is immediately east of the confluence of Cherry Creek and the South Platte River, approximately 12 mi (19 km) east of the foothills of the Rocky Mountains. Denver is named after James W. Denver, a governor of the Kansas Territory. It is nicknamed the Mile High City because its official elevation is exactly one mile (5280 feet or 1609.
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.