10 Calcium Element Facts You Should Know

10 Calcium Element Facts You Should Know Calcium is one of the elements you need in order to live, so its worth knowing a little bit about it. Here are some quick facts about the element calcium. Fast Facts: Calcium Element Name: CalciumElement Symbol: CaAtomic Number: 20Standard Atomic Weight: 40.078Discovered By: Sir Humphry DavyClassification: Alkaline Earth MetalState of Matter: Solid Metal Calcium is element atomic number 20 on the periodic table, which means each atom of calcium has 20 protons. It has the periodic table symbol Ca and an atomic weight of 40.078. Calcium isnt found free in nature, but it can be purified into a soft silvery-white alkaline earth metal. Because the alkaline earth metals are reactive, pure calcium typically appears dull white or gray from the oxidation layer that quickly forms on the metal when its exposed to air or water.  The pure metal can be cut using a steel knife.Calcium is the 5th most abundant element in the Earths crust, present at a level of about 3% in the oceans and soil. The only metals more abundant in the crust are iron and aluminum. Calcium is also abundant on the Moon. It is present at about 70 parts per million by weight in the solar system.  Natural calcium is a mixture of six isotopes, with the most abundant (97%) being calcium-40.The element is essential for animal and plant nutrition. Calcium participates in many b iochemical reactions, including building skeletal systems, cell signaling, and moderating muscle action.  It is the most abundant metal in the human body, found mainly in bones and teeth. If you could extract all of the calcium from the average adult person, youd have about 2 pounds (1 kilogram) of the metal.  Calcium in the form of calcium carbonate is used by snails and shellfish to construct shells. Dairy products and grains are the primary sources of dietary calcium, accounting or about three-quarters of dietary intake. Other sources of calcium include protein-rich foods, vegetables, and fruits.Vitamin D is essential for calcium absorption by the human body. Vitamin D is converted to a hormone which causes intestinal proteins responsible for calcium absorption to be produced.Calcium supplementation is controversial. While calcium and its compounds are not considered to be toxic, ingesting too many calcium carbonate dietary supplements or antacids can cause milk-alkali syndrome, which is associated with hypercalcemia sometimes leading to fatal renal failure. Excessive consumption would be on the order of 10 g calcium carbonate/day, though symptoms have been reported upon ingesting as little as 2.5 g calcium carbonate daily.  Excessive calcium consumption has been linked to kidney stone formation and artery calcification.Calcium is used for making cement, making cheese, removin g nonmetallic impurities from alloys, and as a reduction agent in the preparation of other metals.  The Romans used to heat limestone, which is calcium carbonate, to make calcium oxide. The calcium oxide was mixed with water to make cement, which was mixed with stones to build aqueducts, amphitheaters, and other structures that survive to the present day. Pure calcium metal reacts vigorously and sometimes violently with water and acids.  The reaction is exothermic. Touching calcium metal can cause irritation or even chemical burns. Swallowing calcium metal can be fatal.The element name calcium comes from the Latin word calcis or calx  meaning lime.  In addition to occurrence in lime (calcium carbonate), calcium is found in the minerals gypsum (calcium sulfate) and fluorite (calcium fluoride).Calcium has been known since the 1st century, when the ancient Romans were known to make lime from calcium oxide.  Natural calcium compounds are readily available in the form of calcium carbonate deposits, limestone, chalk, marble, dolomite, gypsum, fluorite, and apatite.Though calcium has been known for thousands of years, it was not purified as an element until 1808 by Sir Humphry Davy (England). Thus, Davy is considered to be the discoverer of calcium. Sources Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 112.Parish, R. V. (1977).  The Metallic Elements. London: Longman. p.  34.Weast, Robert (1984).  CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp.  E110.​

This Charette is Not A Tumbril

This Charette is Not A Tumbril This Charette is Not A Tumbril This Charette is Not A Tumbril By Maeve Maddox The high school in my community is about to undergo a major redesign. I opened the morning paper and read the following headline: Details of tonights high school design charette revealed Wednesday I was puzzled because the only meaning for charette/charrette I was acquainted with was wheeled cart, like the one that hauled Sidney Carton to the guillotine in A Tale of Two Cities. Come to find out, charette, also spelled charet, is a term much used in urban planning. Heres the new definition as added to the OED in 2007 charet, n. Chiefly N. Amer. (orig. Archit.). A period of intense (group) work, typically undertaken in order to meet a deadline. Also: a collaborative workshop focusing on a particular problem or project; (Town Planning) a public meeting or conference devoted to discussion of a proposed community building project. [Probably originally with reference to the former custom among French architecture students of using a cart to carry their work on the day of an exhibition: see Trà ©sor de la Langue Franà §aise s.v. charrette.] Now I understand when I read something like the following: Herbert said that during the charette, boards will be provided with outlines of the campus. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Vocabulary category, check our popular posts, or choose a related post below:Farther vs. Further50 Idioms About Roads and PathsPhrasal Verbs and Phrasal Nouns