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Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium.
In 1815, Humphry Davy invented the Davy lamp, which allowed miners within coal mines to work safely in the presence of flammable gases. There had been many mining explosions caused by firedamp or methane often ignited by open flames of the lamps then used by miners. Davy conceived of using an iron gauze to enclose a lamp's flame, and so prevent ...
Sir Humphry Davy, 1st Baronet, FRS, MRIA, FGS (17 December 1778 – 29 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp.
Scheele showed that scheelite (then called tungsten) was a salt of calcium with a new acid, which he called tungstic acid. The Elhuyars obtained tungstic acid from wolframite and reduced it with charcoal, naming the element "volfram". [1] [87] Since that time both names, tungsten and wolfram, have been used depending on language. [1]
A coronary CT calcium scan is a computed tomography (CT) scan of the heart for the assessment of severity of coronary artery disease. Specifically, it looks for calcium deposits in atherosclerotic plaques in the coronary arteries that can narrow arteries and increase the risk of heart attack. [ 1 ]
The reaction of calcium carbide with water, producing acetylene and calcium hydroxide, [5] was discovered by Friedrich Wöhler in 1862. CaC 2 ( s ) + 2H 2 O ( l ) → C 2 H 2 ( g ) + Ca(OH) 2 (aq) This reaction was the basis of the industrial manufacture of acetylene , and is the major industrial use of calcium carbide.
Tums (stylized as TUMS) is an antacid made of sucrose (table sugar) and calcium carbonate (CaCO 3) manufactured by Haleon in St. Louis, Missouri, US. They are also available in a sugar-free version. It is an over-the-counter drug, available at many retail stores, including drug stores, grocery stores and mass merchandisers.
In 1892, Willson discovered an economically efficient process for creating calcium carbide, which is used in the production of acetylene gas. In 1895, he sold his patent to Union Carbide. In the same year, Willson married Mary Parks in California and moved back to Canada. He built a house for his mother in Woodstock, Ontario in 1895.