Fluorine Facts - Atomic Number 9 or F

Fluorine Facts - Atomic Number 9 or F Fluorine is a halogen that exists under ordinary conditions as a pale yellow diatomic gas. The element is found in fluoridated water, toothpaste, and refrigerants. Here are facts about this interesting element. Fluorine Atomic Data Atomic Number: 9 Symbol: F Atomic Weight: 18.998403 Discovery: Henri Moissan 1886 (France) Electron Configuration: [He]2s22p5 Word Origin:  The name fluorine comes from the Latin and French fluere: flow or flux. Sir Humphry Davy proposed the element name, based on its presence in fluoric acid. The -ine suffix is consistent with the naming of other halogens. However, the element is named fluor in Greek and Russian. In early papers, it is referred to as fluorum. Properties: Fluorine has a melting point of -219.62 °C (1 atm), boiling point of -188.14 °C (1 atm), density of 1.696 g/l (0 °C, 1 atm), specific gravity of liquid of 1.108 at its boiling point, and valence of 1. Fluorine is a corrosive pale yellow gas. It is highly reactive, participating in reactions with virtually all organic and inorganic substances. Fluorine is the most electronegative element. Metals, glass, ceramics, carbon, and water will burn with a bright flame in fluorine. It is possible that fluorine can substitute for hydrogen in organic reactions. Fluorine has been known to form compounds with rare gases, including xenon, radon, and krypton. Free fluorine has a characteristic pungent odor, detectable at concentrations as low as 20 ppb. Toxicity: Both elemental fluorine and the fluoride ion are highly toxic. The recommended maximum allowable concentration for a daily 8-hour time-weighted exposure is 0.1 ppm. Neither fluorine nor its ion, fluoride, are considered trace nutrients for human nutrition. However, fluoride does impact bone strength. Uses: Fluorine and its compounds are used in producing uranium. Fluorine, in the form of fluorite, is added during smelting to help reduce the melting points of metals. Fluorochlorohydrocarbons are used in refrigeration applications. Fluorine is used to produce many chemicals, including several high-temperature plastics. The presence of sodium fluoride in drinking water at the level of 2 ppm may cause mottled enamel in teeth, skeletal fluorosis, and may be associated with cancer and other diseases. However, topically applied fluoride (toothpaste, dental rinses) may help reduce the incidence of dental caries. Sources: Fluorine occurs in fluorspar (CaF) and cryolite (Na2AF6) and is widely distributed in other minerals. It is obtained by electrolyzing a solution of potassium hydrogen fluoride in anhydrous hydrogen fluoride in container of transparent fluorspar or metal. Element Classification: Halogen Isotopes: Fluorine has 17 known isotopes ranging from F-15 to F-31. F-19 is the only stable and most common isotope of fluorine.Density (g/cc): 1.108 ( -189 °C) Appearance:  At room temperature and pressure, pure fluorine is a very pale, greenish-yellow, pungent, corrosive gas. Liquid fluorine, like chlorine, is bright yellow. Solid fluorine is found in alpha and beta allotropes. The alpha form is opaque, while the beta form is transparent. Atomic Volume (cc/mol): 17.1 Covalent Radius (pm): 72 Ionic Radius: 133 (-1e) Specific Heat (20 °C J/g mol): 0.824 (F-F) Fusion Heat (kJ/mol): 0.51 (F-F) Evaporation Heat (kJ/mol): 6.54 (F-F) Pauling Negativity Number: 3.98 First Ionizing Energy (kJ/mol): 1680.0 Oxidation States: -1 Lattice Structure: Monoclinic CAS Registry Number: 7782-41-4 Fluorine Trivia Fluorine in the form of the mineral fluorite was used in the 1500s to aid in ore smelting.Fluorine was suspected to be an element as early as 1810 but wasnt successfully isolated until 1886. Many chemists trying to isolate the element would be blinded or even killed by the violent reactions that generally accompany fluorine gas.Henri Moissan earned the 1906 Nobel Prize in Chemistry for being the chemist who finally successfully isolated fluorine (and also invented the electric arc furnace).Fluorine is the 13th most common element in the Earths crust.Fluorine is the 24th most abundant in the universe. Fluorine Fast Facts Element Name: FluorineElement Symbol: FAtomic Number: 9Appearance: Pale yellow gas.Group: Group 17 (Halogen)Period: Period 2Discovery: Henri Moissan (June 26, 1886) Sources Emsley, John (2011). Natures Building Blocks: An A–Z Guide to the Elements (2nd ed.). Oxford: Oxford University Press. ISBN 978-0-19-960563-7.Greenwood, N. N.; Earnshaw, A. (1998). Chemistry of the Elements (2nd ed.). Oxford: Butterworth Heinemann. ISBN 0-7506-3365-4.Moissan, Henri (1886). Action dun courant à ©lectrique sur lacide fluorhydrique anhydre. Comptes rendus hebdomadaires des sà ©ances de lAcadà ©mie des sciences (in French). 102: 1543–1544.Nielsen, Forrest H. (2009). Micronutrients in Parenteral Nutrition: Boron, Silicon, and Fluoride. Gastroenterology. 137 (5): S55–60. doi:10.1053/j.gastro.2009.07.072Patnaik, Pradyot (2007). A Comprehensive Guide to the Hazardous Properties of Chemical Substances (3rd ed.). Hoboken: John Wiley Sons. ISBN 978-0-471-71458-3.

Countries With Negative Population Growth

Countries With Negative Population Growth Data from the Population Reference Bureau showed in 2006 that there were 20 countries in the world with negative or zero natural population growth expected between 2006 and 2050.   What Does Negative Natural Population Growth Mean? This negative or zero natural population growth means that these countries have more deaths than births or an even number of deaths and births; this figure does not include the effects  of immigration or emigration. Even including immigration over emigration, only one of the 20 countries (Austria) was expected to grow between 2006 and 2050, though the rush of emigration from wars in the Middle East (especially Syrias civil war) and Africa in the mid-2010s could revise those expectations. The Highest Decreases The country with the highest decrease in the natural birthrate was  Ukraine, with a natural decrease of 0.8 percent  each year. Ukraine was expected to lose 28 percent  of its  population between 2006 and 2050 (from 46.8 million to 33.4 million in 2050). Russia and Belarus followed close behind at a 0.6 percent  natural decrease, and Russia was expected to lose 22 percent  of its population by 2050, which would be a loss of more than 30 million people (from 142.3 million in 2006 to 110.3 million in 2050). Japan was the only non-European country in the list, though China joined it after the list was released and had a lower-than-replacement birthrate in the mid-2010s.  Japan has a 0 percent natural birth increase and was expected to lose 21 percent  of its population between 2006 and 2050 (shrinking from 127.8 million to a mere 100.6 million in 2050).   A List of Countries With Negative Natural Increase Heres the list of the countries that were expected to have a negative natural increase or zero increase in population between 2006 and 2050. Ukraine: 0.8% natural decrease annually; 28% total population decrease by 2050Russia: -0.6%; -22%Belarus: -0.6%; -12%Bulgaria: -0.5%; -34%Latvia: -0.5%; -23%Lithuania: -0.4%; -15%Hungary: -0.3%; -11%Romania: -0.2%; -29%Estonia: -0.2%; -23%Moldova: -0.2%; -21%Croatia: -0.2%; -14%Germany: -0.2%; -9%Czech Republic: -0.1%; -8%Japan: 0%; -21%Poland: 0%; -17%Slovakia: 0%; -12%Austria: 0%; 8% increaseItaly: 0%; -5%Slovenia: 0%; -5%Greece: 0%; -4% In 2017, the Population Reference Bureau released a fact sheet showing that the top five countries expected to lose population between then and 2050 were:China: -44.3%Japan: -24.8%Ukraine: -8.8%Poland: -5.8%Romania: -5.7%Thailand: -3.5%Italy: -3%South Korea: -2.2%