Tuesday, March 17, 2020

Radon Chemical and Physical Properties

Radon Chemical and Physical Properties Atomic Number: 86 Symbol: Rn Atomic Weight: 222.0176 Discovery: Fredrich Ernst Dorn 1898 or 1900 (Germany), discovered the element and called it radium emanation. Ramsay and Gray isolated the element in 1908 and named it niton. Electron Configuration: [Xe] 4f14 5d10 6s2 6p6 Word Origin: from radium. Radon was once called niton, from the Latin word nitens, which means shining Isotopes: At least 34 isotopes of radon are known ranging from Rn-195 to Rn-228. There are no stable isotopes of radon. The isotope radon-222 is the most stable isotope and called thoron and emanates naturally from thorium. Thoron is an alpha-emitter with a half-life of 3.8232 days. Radon-219 is called actinon and emanates from actinium. It is an alpha-emitter with a half-life of 3.96 sec. Properties: Radon has a melting point of -71Â °C, boiling point of -61.8 Â °C, gas density of 9.73 g/l, specific gravity of the liquid state of 4.4 at -62Â °C, specific gravity of the solid state of 4, usually with a valence of 0 (it does form some compounds, however, such as radon fluoride). Radon is a colorless gas at normal temperatures. It is also the heaviest of the gases. When it is cooled below its freezing point it displays a brilliant phosphorescence. The phosphorescence is yellow as the temperature is lowered, becoming orange-red at the temperature of liquid air. Inhalation of radon presents a health risk. Radon build-up is a health consideration when working with radium, thorium, or actinium. It is also a potential issue in uranium mines. Sources: It is estimated that each square mile of soil to a depth of 6 inches contains approximately 1 g of radium, which releases radon to the atmosphere. The average concentration of radon is about 1 sextillion parts of air. Radon naturally occurs in some spring waters. Element Classification: Inert Gas Physical Data Density (g/cc): 4.4 ( -62Â °C) Melting Point (K): 202 Boiling Point (K): 211.4 Appearance: heavy radioactive gas Specific Heat (20Â °C J/g mol): 0.094 Evaporation Heat (kJ/mol): 18.1 First Ionizing Energy (kJ/mol): 1036.5 Lattice Structure: Face-Centered Cubic CAS Registry Number: 10043-92-2 Trivia Ernest Rutherford is sometimes credited with the discovery of radon. He actually discovered the alpha particle radiation given off by radon.Radon became the official name for element 86 in 1923. The IUPAC chose radon from the names radon (Rn), thoron (Tn) and actinon (An). The other two names are given to isotopes of radon. Thoron is Rn-220 and actinon became Rn-219.Other suggested names for radon included radium emanation, niton, extadio, exthorio, exactinio, akton, radeon, thoreon and actineon.The U.S. Environmental Protection Agency lists radon as the second highest cause of lung cancer. References Los Alamos National Laboratory (2001)Crescent Chemical Company (2001)Langes Handbook of Chemistry (1952)CRC Handbook of Chemistry Physics (18th Ed)International Atomic Energy Agency ENSDF database (Oct 2010)

Sunday, March 1, 2020

Negro Baseball League Timeline

Negro Baseball League Timeline The Negro Baseball Leagues were professional leagues in the United States for players of African descent. At its height of popularity- from 1920 through World War II- Negro  Baseball Leagues were an integral part of African-American life and culture during the Jim Crow Era.   1859: The first documented baseball game between two African-American teams is played on November 15 in New York City. The Henson Baseball Club of Queens played the Unknowns of Brooklyn. The Henson Baseball Club defeated the Unknowns, 54 to 43. 1885: The first African-American professional team is founded in Babylon, NY. They are named the Cuban Giants. 1887: The National Colored Baseball League is established, becoming the first professional African-American league. The league begins with eight teams- the Lord Baltimores, Resolutes, Browns, Falls City, Gorhams, Pythians, Pittsburgh Keystones, and the Capital City Club. However, within two weeks the National Colored Baseball League will cancel games as a result of poor attendance. 1890: The International League bans African-American players, which will last until 1946. 1896:  The Page Fence Giants club is established by Bud Fowler. The club is considered one of the best teams in early African-American baseball history because players toured in their own railroad car and played against major league teams such as the Cincinnati Reds. 1896: The United States Supreme Court upholds Louisianas separate but equal laws concerning public facilities. This decision affirms racial segregation, de facto segregation, and prejudice throughout the United States. 1896: The Page Fence Giants and Cuban Giants play a national championship. The Page Fence Club wins 10 out of 15 games. 1920: At the height of the Great Migration, Andrew Rube Foster, owner of the Chicago American Giants organizes a meeting with all the Midwest team owners in Kansas City. As a result, the Negro National League is established. 1920: On May 20, the Negro National League begins its first season with seven teamsthe Chicago American Giants, Chicago Giants, Dayton Marcos, Detroit Stars, Indianapolis ABCs, Kansas City Monarchs and Cuban Stars. This marks the beginning of the Golden Era of Negro Baseball. 1920: The Negro Southern League is established. The league includes cities such as Atlanta, Nashville, Birmingham, Memphis, New Orleans, and Chattanooga. 1923: The Eastern Colored League is established by Ed Bolden, owner of the Hilldale Club, and Nat Strong, owner of the Brooklyn Royal Giants. The Eastern Colored League consists of the following six teams: Brooklyn Royal Giants, Hilldale Club, Bacharach Giants, Lincoln Giants, Baltimore Black Sox, and the Cuban Stars. 1924: The Kansas City Monarchs of the Negro National League and the Hilldale Club of the Eastern Colored League play in the first Negro World Series. The Kansas City Monarchs win the championship five games to four. 1927 - 1928: The Eastern Colored League faces many conflicts between various club owners. In 1927, New Yorks Lincoln Giants left the league. Although the Lincoln Giants returned in the following season, several other teams including the Hilldale Club, Brooklyn Royal Giants, and Harrisburg Giants all left the league. In 1928, the Philadelphia Tigers were brought into the league. Despite several attempts, the League disbands in June of 1928 over player contracts. 1928: The American Negro League is developed and includes the Baltimore Black Sox, Lincoln Giants, Homestead Grays, Hilldale Club, Bacharach Giants, and the Cuban Giants. Many of these teams were members of the Eastern Colored League. 1929: The stock market crashes, placing financial strains on many facets of American life and business, including Negro League baseball as ticket sales slump. 1930: Foster, founder of the Negro National League dies. 1930: The Kansas City Monarchs end their ties with the Negro National League and become an independent team. 1931: The Negro National League disbands after the 1931 season as a result of financial strains. 1932: The Negro Southern League becomes the only major African-American baseball league operating. Once considered less lucrative than other leagues, the Negro Southern League is able to begin the season with five teams including the Chicago American Giants, Cleveland Cubs, Detroit Stars, Indianapolis ABCs, and Louisville White Sox. 1933: Gus Greenlee, a business owner from Pittsburgh forms the new Negro National League. Its first season begins with seven teams. 1933: The inaugural East-West Colored All-Star Game is played at Comiskey Park in Chicago. An estimate 20,000 fans attend and the West wins, 11-7. 1937: The Negro American League is established, uniting the strongest teams on the West Coast and south. These teams included the Kansas City Monarchs, Chicago American Giants, Cincinnati Tigers, Memphis Red Sox, Detroit Stars, Birmingham Black Barons, Indianapolis Athletics, and St. Louis Stars. 1937: Josh Gibson and Buck Leonard help the Homestead Grays begin its nine-year streak as champions of the Negro National League. 1946: Jackie Robinson, a player for the Kansas City Monarchs, is signed by the Brooklyn Dodgers organization. He plays with the Montreal Royals and becomes the first African-American to play in the International League in more than sixty years. 1947: Robinson becomes the first African-American player in major league baseball by joining the Brooklyn Dodgers. He wins National League Rookie of the Year. 1947: Larry Doby becomes the first African-American player in the American League when he joins the Cleveland Indians. 1948: The Negro National League disbands. 1949: The Negro American League is the only major African-American league still playing. 1952: More than 150 African-American baseball players, most from the Negro Leagues, have been signed to Major League Baseball. With low ticket sales and a lack of good players, the era of African-American baseball comes to an end.