Cobalt vs Athen

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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

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Athens ( ATH-inz; Greek: Αθήνα, romanized: Athína [aˈθina] (listen); Ancient Greek: Ἀθῆναι, romanized: Athênai (pl.) [atʰɛ̂ːnai̯]) is the capital and largest city of Greece. Athens dominates the Attica area and is one of the world's oldest cities, with its history spanning over 3,400 decades and its earliest human presence started somewhere between the 11th and 7th century BC.Classical Athens was a strong city-state. A centre for the arts, learning and philosophy, home of Plato's Academy and Aristotle's Lyceum, it is widely referred to as the cradle of Western civilization and the birthplace of democracy, largely due to its cultural and political effect on the European continent, and particularly the Romans. These days, Athens is a large cosmopolitan metropolis and central to economic, financial, industrial, marine, cultural and political life in Greece. Athens is a Beta worldwide city based on the Globalization and World Cities Research Network, and is one of the biggest economic centers in southeastern Europe. It has a large financial industry, and its port Piraeus is both the largest passenger port in Europe, and the second largest in the world.The Municipality of Athens (also City of Athens), which really constitutes a tiny administrative unit of the entire city, had a population of 664,046 (in 2011) within its official limits, and a land area of 38.96 km2 (15.04 sq mi). The Athens Urban Area (Greater Athens and Greater Piraeus) extends beyond its administrative municipal city limits, with a population of 3,090,508 (in 2011) within an area of 412 km2 (159 sq mi). According to Eurostat in 2011, the functional urban area (FUA) of Athens was the 9th most populous FUA in the European Union (the 6th most populous capital city of the EU), with a population of 3.

8 million people. Athens is also the southernmost capital on the European mainland and the warmest major city in Europe. The heritage of the classical era is still evident in the city, represented by ancient monuments and works of art, the most famous of all being the Parthenon, considered a key landmark of ancient Western civilization. The town also retains Roman and Byzantine monuments, in addition to a smaller number of Ottoman monuments, while its historical urban center features elements of continuity through its millennia of history. Athens is home to two UNESCO World Heritage Sites, the Acropolis of Athens and the medieval Daphni Monastery. Landmarks of the modern age, dating back to the establishment of Athens as the capital of the independent Greek state in 1834, include the Hellenic Parliament and the so-called"architectural trilogy of Athens", comprising the National Library of Greece, the National and Kapodistrian University of Athens and the Academy of Athens. Athens is also home to several museums and cultural institutions, like the National Archeological Museum, featuring the world's largest collection of ancient Greek antiquities, the Acropolis Museum, the Museum of Cycladic Art, the Benaki Museum and the Byzantine and Christian Museum. Athens was the host city of the first modern-day Olympic Games in 1896, and 108 decades after it hosted the 2004 Summer Olympics, which makes it one of the few cities to have hosted the Olympics more than once.

Source: Wikipedia