Volgograd vs Cobalt

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Volgograd (Russian: Волгогра́д), formerly Tsaritsyn (Цари́цын) (1589–1925), and Stalingrad (Сталингра́д) (1925–1961), is the largest city and the administrative centre of Volgograd Oblast, Russia. The city lies on the western bank of the Volga, covering an area of 859.4 square kilometres (331.8 square miles), with a population of over 1 million residents. Volgograd is the fifteenth-largest city in Russia, the second-largest city on the Southern Federal District, and the fourth-largest city on the Volga. The city was founded as the fortress of Tsaritsyn in 1589. By the nineteenth century, Tsaritsyn became an important river-port and commercial centre, leading to its population expanding rapidly. During the Russian Civil War, Tsaritsyn came under Soviet control. On April 10, 1925, the city was renamed Stalingrad in honor of Joseph Stalin.

During World War II, the Axis forces attacked the city, leading to the Battle of Stalingrad, one of the largest and bloodiest battles in the history of warfare. On 10 November 1961, Nikita Khrushchev's administration changed the name of the city to Volgograd. After the dissolution of the Soviet Union, the city became the administrative centre of Volgograd Oblast. Known locally as the "Hero City", Volgograd today is the site of The Motherland Calls, an 85-meter high statue dedicated to the heroes of the battle, which is the tallest statue in Europe, as well as the tallest statue of a woman in the world. The city has many tourist attractions, such as museums, sandy beaches, and a self-propelled floating church. Volgograd was one of the host cities of the 2018 FIFA World Cup.

Source: Wikipedia

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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.

The copper belt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. World production in 2016 was 116,000 metric tons (114,000 long tons; 128,000 short tons) (according to Natural Resources Canada), and the DRC alone accounted for more than 50%.Cobalt is primarily used in lithium-ion batteries, and in the manufacture of magnetic, wear-resistant and high-strength alloys. The compounds cobalt silicate and cobalt(II) aluminate (CoAl2O4, cobalt blue) give a distinctive deep blue color to glass, ceramics, inks, paints and varnishes. Cobalt occurs naturally as only one stable isotope, cobalt-59. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy gamma rays. Cobalt is the active center of a group of coenzymes called cobalamins. Vitamin B12, the best-known example of the type, is an essential vitamin for all animals. Cobalt in inorganic form is also a micronutrient for bacteria, algae, and fungi.

Source: Wikipedia