School Ties essays

School Ties essays School Ties, a film by Robert Mandel, is the story of a Jewish boy, David Greene, who is recruited to play football for an elite private school. David Greene hides his religion from his schoolmates and teachers because the school is made up of Christians. Soon after David begins to feel accepted by his classmates, Charlie Dillon, a jealous rival of Greene's, exposes him as being Jewish. All of Greene's friends turn on him and David begins to be tormented by his peers. Later, Dillion cheats on a test. The teacher decides that unless the cheater comes forward, he will fail the entire class. While the classmates are deciding who the culprit is, a momentum is built and the students begin to behave differently than they would if group did not surround them. The classmates turn on Greene even though a few of them originally thought that Dillion cheated. This change in behavior due to the safeness of a crowd mixed with fear, panic, and ignorance is called a mob mentality. The first instance of mob mentality in School Ties occurs soon after the students discover that David Greene is Jewish. The students turn on David and begin to be hurtful toward him. A few students try to intercede by asking each other questions like "Well how many Jews have you had in your house?" Most of the students had never directly met a Jewish person. The ignorant students assumed that Jewish people were money-hungry and generally bad people because of what they had heard from other people. David's peers were scared because they believed that David's religion changed who he was as a person and it separated him from them. Chris Reece, David's room-mate asked David why he didn't tell him that he was Jewish. David retorted by asking Chris Reece what religion he was and why he had not told David before. The students believed that David's religion was so different and foreign and that it seperated them so much that it was his duty to inform them. ...

Electron Affinity (Chemistry Glossary Definition)

Electron Affinity (Chemistry Glossary Definition) Electron affinity reflects the ability of an atom to accept an electron. It is the energy change that occurs when an electron is added to a gaseous atom. Atoms with stronger effective nuclear charge have greater electron affinity. The reaction that occurs when an atom takes an electron may be represented as: X e−  Ã¢â€ â€™ X−   energy Another way to define electron affinity is as the amount of energy needed to remove an electron from a singly charged negative ion: X−  Ã¢â€ â€™ X e− Key Takeaways: Electron Affinity Definition and Trend Electron affinity is the amount of energy required to detach one electron from a negatively charged ion of an atom or molecule.It is indicated using the symbol Ea and is usually expressed in units of kJ/mol.Electron affinity follows a trend on the periodic table. It increases moving down a column or group and also increases moving from left to right across a row or period (except for the noble gases).The value may be either positive or negative. A negative electron affinity means energy must be input in order to attach an electron to the ion. Here, electron capture is an endothermic process. If electron affinity is positive, the process is exothermic and occurs spontaneously. Electron Affinity Trend Electron affinity is one of the trends that can be predicted using the organization of elements in the periodic table. Electron affinity increases moving down an element group (periodic table column).Electron affinity generally increases moving left to right across an element period (periodic table row). The exception is the noble gases, which are in the last column of the table. Each of these elements has a completely filled valence electron shell and an electron affinity approaching zero. Nonmetals typically have higher electron affinity values than metals. Chlorine strongly attracts electrons. Mercury is the element with atoms that most weakly attract an electron. Electron affinity is more difficult to predict in molecules because their electronic structure is more complicated. Uses of Electron Affinity Keep in mind, electron affinity values only apply to gaseous atoms and molecules because the electron energy levels of liquids and solids are altered by interaction with other atoms and molecules. Even so, electron affinity has practical applications. It is used to measure chemical hardness, a measure of how charged and readily polarized Lewis acids and bases are. Its also used to predict electronic chemical potential. The primary use of electron affinity values is to determine whether an atom or molecule will act as an electron acceptor or an electron donor and whether a pair of reactants will participate in charge-transfer reactions. Electron Affinity Sign Convention Electron affinity is most often reported in units of kilojoule per mole (kJ/mol). Sometimes the values are given in terms of magnitudes relative to each other. If the value of electron affinity or Eea is negative, it means energy is required to attach an electron. Negative values are seen for the nitrogen atom and also for most captures of second electrons. It can also be seen for surfaces, such as diamond. For a negative value, the electron capture is an endothermic process: Eea   −ΔE(attach) The same equation applies if Eea  has a positive value. In this situation the change ΔE  has a negative value and indicates an exothermic process. Electron capture for most gas atoms (except noble gases) releases energy and is exothermic. One way to remember capturing an electron has a negative ΔE  is to remember energy is let go or released. Remember: ΔE  and Eea  have opposite signs! Example Electron Affinity Calculation The electron affinity of hydrogen is ΔH in the reaction: H(g) e- → H-(g); ΔH -73 kJ/mol, so the electron affinity of hydrogen is 73 kJ/mol. The plus sign isnt cited, though, so the Eea  is simply written as 73 kJ/mol. Sources Anslyn, Eric V.; Dougherty, Dennis A.  (2006). Modern Physical Organic Chemistry. University Science Books. ISBN 978-1-891389-31-3.Atkins, Peter; Jones, Loretta (2010). Chemical Principles the Quest for Insight. Freeman, New York. ISBN 978-1-4292-1955-6.Himpsel, F.; Knapp, J.; Vanvechten, J.; Eastman, D. (1979). Quantum photoyield of diamond(111)- A stable negative-affinity emitter. Physical Review B. 20 (2): 624. doi:10.1103/PhysRevB.20.624Tro, Nivaldo J. (2008). Chemistry: A Molecular Approach (2nd Ed.). New Jersey: Pearson Prentice Hall. ISBN 0-13-100065-9.IUPAC (1997). Compendium of Chemical Terminology (2nd Ed.) (the Gold Book). doi:10.1351/goldbook.E01977