Coordination Number Definition in Chemistry

Coordination Number Definition in Chemistry The coordination number of an atom in a molecule is the number of atoms bonded to the atom. In chemistry and crystallography, the coordination number describes the number of neighbor atoms with respect to a central atom. The term was originally defined in 1893 by Swiss chemist Alfred Werner (1866–1919). The value of the coordination number is determined differently for crystals and molecules. The coordination number can vary from as low as 2 to as high as 16. The value depends on the relative sizes of the central atom and ligands and by the charge from the electronic configuration of an ion. The coordination number of an atom in a molecule or polyatomic ion is found by counting the number of atoms bound to it (note, not by counting the number of chemical bonds). Its more difficult to determine chemical bonding in solid-state crystals, so the coordination number in crystals is found by counting the number of neighboring atoms. Most commonly, the coordination number looks at an atom in the interior of a lattice, with neighbors extending in all directions. However, in certain contexts crystal surfaces are important (e.g., heterogeneous catalysis and material science), where the coordination number for an interior atom is the bulk coordination number and the value for a surface atom is the surface coordination number. In coordination complexes, only the first (sigma) bond between the central atom and ligands counts. Pi bonds to the ligands are not included in the calculation. Coordination Number Examples Carbon has a coordination number of 4 in a methane (CH4) molecule since it has four hydrogen atoms bonded to it.In ethylene (H2CCH2), the coordination number of each carbon is 3, where each C is bonded to 2H 1C for a total of 3 atoms.The coordination number of diamond is 4, as each carbon atom rests at the center of a regular tetrahedron formed by four carbon atoms. Calculating the Coordination Number Here are the steps for identifying the coordination number of a coordination compound. Identify the central atom in the chemical formula. Usually, this is a transition metal.Locate the atom, molecule, or ion nearest the central metal atom. To do this, find the molecule or ion directly beside the metal symbol in the chemical formula of the coordination compound. If the central atom is in the middle of the formula, there will be neighboring atoms/molecules/ions on both sides.Add the number of atoms of the nearest atom/molecule/ions. The central atom may only be bonded to one other element, but you still need to note the number of atoms of that element in the formula. If the central atom is in the middle of the formula, youll need to add up the atoms in the entire molecule.Find the total number of nearest atoms. If the metal has two bonded atoms, add together both numbers, Coordination Number Geometry There are multiple possible geometric configurations for most coordination numbers. Coordination Number 2- linearCoordination Number 3- trigonal planar (e.g., CO32-), trigonal pyramid, T-shapedCoordination Number 4- tetrahedral, square planarCoordination Number 5- square pyramid (e.g., oxovanadium salts, vanadyl VO2), trigonal bipyramid,  Coordination Number 6- hexagonal planar, trigonal prism, octahedralCoordination Number 7- capped octahedron, capped trigonal prism, pentagonal bipyramidCoordination Number 8- dodecahedron, cube, square antiprism, hexagonal bipyramidCoordination Number 9- three-face centered trigonal prismCoordination Number 10- bicapped square antiprismCoordination Number 11- all-faced capped trigonal prismCoordination Number 12- cuboctahedron (e.g., Ceric ammonium nitrate -(NH4)2Ce(NO3)6)

Dissent Theory Profile Essay Example | Topics and Well Written Essays - 500 words

Dissent Theory Profile - Essay Example Usually in a group, there are two types of people: there are those who identify strongly with the group and others who have weak identification with the group. Those are who are strongly identified are the ones prone to dissent from the norms in order to protect the rest of their social group and their identities from outside forces in every way they deem possible. What is astonishing about the theory is that these same people who are strongly identified with the group will not easily and quickly dissent if the challenge is not on their group but on themselves as individuals. This provides a strong sense of how deeply these people feel about their social group which they identify with and the extent they can go to for the group which is not even the same they can go for themselves. The weak identifiers with the group are the exact opposite of the strong identifiers as they cannot go an extra mile (such as challenging the system or dissenting) for their social group members but when it comes to them, they will act to protect themselves more than the strong identifiers do to themselves. Weak identifiers are just an indication of the non-conformity that arises out of some people being disengaged from the group norm while strong identifiers are an indication of the non-conformity that arises out of desire to help group members or even change the group. The aspect of social interaction is important for this group of people and anyone or anything trying to challenge this social interaction is deemed an enemy and must be fought with or discouraged to continue doing so. It is for this reason of trying to protect their social interaction and identities to each other that people find the need to dissent. The reason for the dissent is justifiable as they are protecting not only their organizational duties but their social and psychological ones as well (Kassing, 2011). The dissent may even be an organizational norm but this does not matter and

A Case Study of Medical Supplies Ltd Essay Example | Topics and Well Written Essays - 2000 words

A Case Study of Medical Supplies Ltd - Essay Example ares many of the same pluralistic values as Steele, however the nature by which Harry runs his operation is one with more respect for subordinates in terms of recognizing their overall value to the firm. This paper will describe the scenarios which are causing trouble within Medical Supplies Ltd and will propose a potential solution for handling the crises. The leadership hierarchy at Medical Supplies, Ltd is one that is highly mechanistic, which is categorised by decision-making that is made at the management level without considering the input of subordinate employees; in which employees are simply expected to conform to management directives (Landy & Conte, 2006). Gordon Steele recognises his absolute authority over the entire warehouse, including all of its divisional managers and he expects compliance to all corporate objectives and procedures from his subordinate management staff. Steele appears to have a considerable respect for the nature of the authoritarian hierarchy in which power is distributed from a centralised entity, in this case the corporate office. Many of Steele’s beliefs regarding politics are fundamentally pluralistic. Reynolds (1996) suggests that pluralistic leaders often believe that democratic systems, in which individuals are given the autonomy to vote and assist in decision-making, are both unworkable and undesirable. The author further implies that pluralistic leaders tend to believe that subordinates lack the tangible ability to intellectually contribute to policy-making and lack the rationale to provide assistance in all aspects of decision-making. Under this assumption, Steele can be categorised as pluralistic, sharing these values as he routinely cites the various character flaws of his subordinate manager Harry Katama to all levels of the business. When Steele is discussing the nature of employment under Katama, he consistently identifies that their associate workers will be both low-skilled and not generally intelligent. This

Research Methods Coursework Example | Topics and Well Written Essays - 250 words

Research Methods - Coursework Example County hospital records detailing the age, ethnicity, level of education, gender, etc. of each individual treated for drug overdose during the period in which the spike is usually recorded, from the time when it became prevalent; The list is by no means exhaustive. However, in analyzing these records, frequency distribution will most likely isolate a major group or two, which will facilitate success in further investigation. In dealing with a subject of such nature, this research method is arguably more effective than a survey, which, according to Wikipedia, depends on â€Å"subjects’ motivation, honesty, memory, and ability to respond.† Drug users may not be willing respondents in a survey. Observer participation is another method that is very useful not only when â€Å"the phenomenon is sufficiently limited in size and location to be studied as a case† but also when â€Å"the phenomenon is hidden from public view (crime and deviance, secretive groups and organizations, such as drug users & dealers†¦)† (Jorgensen, 1989; 13). The data obtained from the statistical analysis of official records is the blueprint upon which this research method will be employed. That is, the group(s) that most frequently occur(s) in his analysis will be the focus. In a manner of investigation, the researcher can ease himself into the social environment of the group(s) in question, within and (if his study demands) outside the period in which drug overdose is common. Here, â€Å"the research problem can be addressed by qualitative data gathered by direct observation and other means pertinent to the field setting† (Jorgensen, 1989; 13), thereby helping the researcher gain firsthand information on the attitudes, behavior, practices and habits of (each of) the group(s) in question. This ‘investigation’ will most likely see them open up about drug

Symbols Of Truth in Langston Hughes On The Road Essay -- Road Langsto

Langston Hughes uses beautiful symbolism and imagery in his literary work â€Å"On the Road†. Hughes offers up the idea that if one is to open ones heart; life will provide unlimited abundance. In this literary work, Langston Hughes uses nature to demonstrate and symbolize the unwillingness of his main character, Sargeant, to participate in life. Hughes also demonstrates the use of a person’s anger and instinct to survive and how they both can be used as powerful forces in breaking down racial barriers. Another more impacting symbol Hughes uses is Jesus Christ as a metaphor. Hughes uses this to show how people experience life and how the traditional church values contradict each other when it comes to the acceptance of human beings. Therefore after reading â€Å"On the Road†, the views of nature, racial barriers, and values are explained to the readers and the power behind them. To begin with, Langston Hughes uses nature to demonstrate the distinct relationship amongst blacks and whites during the depression. The writing shows the relationship between the different races amongst the men and women. Hughes use of the snow and night express a simple point, but through the use of these metaphors, he enables the story to be a little less invasive and more appealing to the reader. His main character, Sargeant, is left doubting the integrity of life. Hughes wrote, "Sargeant didn't see the snow, not even under the bright lights of the main street, falling white and flaky against the night. He was too hungry, too sleepy, too tired"(296). Langston Hughes stated like this because at the time Sargeant was one minded and did not take the time to notice the beauty and lessons that nature was showing to him. For almost two hundred years white people hav... ...argeant did not see Jesus Christ in the real world, but in his dreams he was able to experience what he needed. Hughes instills that just because you can not see something does not mean that it does not exist. Also that most will only hear what they want to hear. In the end we find that Langston Hughes use of symbolism re-enforce the points he is expressing. In â€Å"On the Road† nature, racism, and values are the three main points and Hughes was trying to express. Sargeant faced many hardships and tasks in his life. Langston Hughes wrote about these hard times from his experiences and the time period he was in. The tension that arose throughout the story by having a down and out black man survive, by using his faith and power of will. No society or way of life was going to take Sargeant down without a fight and Hughes echoed that throughout the entire literary work.

Symbolism in “A Rose for Emily” by William Faulkner

Abel Girma Mr. Lucky English Language and Literature IB Y1 04 September 2012 Word Count: 1087 The Consciousness of Symbolism in â€Å"A Rose For Emily† â€Å"Then we noticed that in the second pillow was the indentation of a head. One of us lifted something from it, and leaning forward, that faint and invisible dust dry and acrid in the nostrils, we saw a long strand of iron-gray hair† read the last lines of â€Å"A Rose for Emily†, a short story written by the American author and Nobel Prize laureate William Faulkner, published in 1931.These last words put a shocking and rather disturbing end to this piece depicting the strange life of Emily Grierson, and her obdurate refusal to adapt to changes in her life, living in her own non-transforming world. Various symbols are used throughout the text although Faulkner did not use any kind of conscious symbolism. The validity of this claim lies in his Nobel Prize in Literature acceptance speech, his biography and his in terview on the meaning of â€Å"A rose for Emily†. Emily Grierson is portrayed as â€Å"A fallen monument† from the very beginning of the story as the narrator starts to describe the ceremonial procedures following her death.Soon after, her home, a â€Å"house that had once been white, decorated with cupolas and spires and scrolled balconies in the heavily lightsome style of the seventies. † (Section I of â€Å"A Rose for Emily) Is adjacently undermined as â€Å"an eyesore among eyesores † (Section I of â€Å"A Rose for Emily), invaded by the deteriorating and industrialized neighborhood that used to be an illustriously reputed neighborhood in the 1970s. This is a fine example of symbolism used in the text as it gives an inkling of the stubbornness in which Emily, a southern woman has lived her life cleaved to the past and immersed in old southern traditions.Similarly, the â€Å"Rose† in â€Å"A Rose for Emily† is a thought-provoking symbo l due to the fact that it is never mentioned throughout the totality of the story. The interpretations of the â€Å"Rose† are unbounded and debatable. It can be understood as being a rose of sympathy Faulkner would like to dedicate to Emily for she had lived an undeniably grim life of solitude and misery. It can equally be interpreted as a rose representing the love Emily desperately needed in her life but never truly found, seeing as a rose generally symbolizes love in most cultures.Likewise, another shock kindling and incontestably pivotal symbol in the story is confined within the last sentence, â€Å"the long strand of iron-gray hair†. These last words reveal the gruesome moral depravity in which Emily lived a great part of her life, sleeping beside the decaying corpse of Homer, the first potential true-love in Emily's life that decided to leave her soon after they started spending a lot of time together. The strand of hair symbolizes the often heretical path which people cross in the quest for love.There is not a clear enough correlation between most of the symbols and what they symbolize for them to have been an application of conscious symbolism. Furthermore Faulkner himself has ascertained that he doesn't rely on consciously using symbolism to channel his philosophies as an author. Effectively, William Faulkner blatantly denies using any conscious symbolism. He explains: â€Å"I was simply trying to write about people [†¦] it was no intention of the writer to say, Now let's see, I'm going to write a piece in which I will use a symbolism [†¦]† (extract from the interview â€Å"A Meaning of â€Å"A Rose for Emily†).This quotation further validates the argument that the symbolism used by Faulkner was unintentional. Ray Bradbury, one of the most renowned American writers of the 20th century explains his take on this topic in a response to a letter from a 16 year old student in 1963. The student wanted to know more abo ut the use of symbolism in literary works so Bradbury stated that â€Å"I never consciously place symbolism in my writing. That would be a self-conscious exercise and self-consciousness is defeating to any creative act. [†¦ ] The best symbolism is always unsuspected and natural. Faulkner also describes his main interest as a writer as being about â€Å"the human heart in conflict with itself† (Nobel Prize acceptance speech). Thus, his sole purpose as a writer goes against the act of using conscious symbolism. Accordingly, in â€Å"A Rose for Emily†, he tells the outlandish, yet compelling story of Miss Emily Grierson's internal conflict in the pursuit of happiness and love that leads her to unorthodox – even satanic – acts. Faulkner's â€Å"A Rose for Emily† offers symbols with limitless interpretations and therefore proves to a considerable extent that the use of those symbols weren't conscious.Moreover, It would be contumelious not to agree with the author when he denies the use of conscious symbolism. Symbolism in â€Å"A Rose for Emily† is consistently present and plays a major role in the possible readers' interpretations of the story's message. However, the use of symbols in a literary work is inevitable and isn't always a product of a conscious act. This means that the fact that there is symbolism in the text isn't a contradiction to the author's initial goal which is writing a mere ghost story inspired by â€Å"a picture of a strand of hair on the pillow in the abandoned house. (Interview on The Meaning of â€Å"A Rose for Emily†). Consequently, the unconscious symbolisms within the story give it sophistication and depth due to its readers' interpretations, not due to the immoral act of imposing symbolism upon them. The American author Isaac Asimov encompasses the answer to the controversy of the use of symbolism in his response to the same letter about from the 16 year old student: â€Å"Conscio usly? Heavens, no! Unconsciously? How can one avoid it? † Faulkner did not use conscious symbolism in â€Å"A Rose for Emily†.Numerous applications of symbolism are present in this short ghost-story and they do hold a non-negligible position in the overall meaning of the piece based on each readers' understanding of them. Nevertheless, the literary virtuoso, William Faulkner did not intentionally place these symbols as a means to convey his message in a latent manner. In lieu of doing so, he straight-forwardly wrote a simple ghost-story containing inevitable symbols. As a matter of fact, we may ask ourselves: to what extent is the conscious use of symbolism in literature in order to convey message, efficient and effective?

French News Vocabulary

The French you learn in classes and grammar books is not always enough when dealing with the real world. This list of French vocabulary related to current events will help you understand news in French. à   la une  - on the front pageles achats de prà ©caution  -  panic buyinglactualità ©, les actualità ©s  -  newsaffolà © (adj)  -  panic-strickenallà ©guà © (adj)  -  allegedun appel  -  appeal, callune arme  -  weapon, gunune arme blanche -  knifeles armes de destruction massive -  weapons of mass destructionassassiner  -  to murderun attentat  -  attackun attentat-suicide  -  suicide bombinglavortement  -  abortionla banlieue  -  suburbun bilan  -  appraisal, assessment, death tollblessà © (adj)  -  injured, woundedune bombe  -  bombla canicule  -  heat waveun cas de force majeure​  -  disaster (natural or man-made)les Casques bleus  -  UN peacekeeping forcesun casseur  -  rioterune catastrophe aà ©rienne  -  air disasterune catastrophe à ©cologique  -  environmental disasterune catastrophe naturelle  -  natural disasterun cessez-le-feu  -  cease-firele chà ´mage  -  unemploymentun collecte au profit des sinistrà ©s  -  disaster fundun coup dEtat  -  coup detat, overthrowune coupure de courant  -  power outagele crime  -  crimeun criminel, une criminelle  -  criminalune crise  -  crisisun cyclone  -  cyclone, hurricanedes dà ©gà ¢ts  -  damagele deuil  -  bereavement, mourningun dà ©sastre financier  -  financial disasterun dà ©sastre politique  -  political disasterles drogues (fem)  -  drugsun à ©boulement  -  rockslideune à ©lection  -  electionune à ©meute  -  riotune enquà ªte  -  investigationune à ©pidà ©mie  -  epidemicextrader  -  to extraditeun feu  -  fireun flic (informal)  -  copla garde à   vue  - police custodyà ªtre mis/placà © en garde à   vue  - to be kept in custody, held for questioningle gaz lacrymogà ¨ne  - tear gasun glissement de terrain  - landslideune grà ¨ve (faire la grà ¨ve)  -  strike (to be on strike)la gu erre  -  warla grippe aviaire  -  bird flula grippe porcine  -  swine fluhexagonal  -  FrenchlHexagone  - Franceun immigrant, un immigrà ©Ã‚  -  immigrantles impà ´ts (masc)  -  taxesun incendie  - fireune inondation  - floodinonder  - to floodun insurgà ©Ã‚  -  insurgentdes intempà ©ries  -  bad weatherIVG  - abortion​le kamikaze  - suicide bomberla loi  - lawla lutte (literal/figurative) - struggle, fightune manifestation  - demonstrationle meurtre  - murderla mondialisation  - globalizationune navette spatiale  - space shuttleun obus  - explosive shellopà ©ration escargot  - rolling blockadeun ouragan  - hurricaneune panne dà ©lectricità ©Ã‚  - blackout, power cutla peine de mort  - death penaltyla pà ©nurie  - shortage, lackla police  - policeun policier  - police officerla politique  -  politics, policyle politique  -  politicianpoursuivre en justice  -  to suele pouvoir dachat  -  bu ying powerprà ©sumà © (adj)  -  allegedun procà ¨s  -  trialle rechauffement de la planà ¨te  -  global warmingla rà ©gion sinistrà ©e  - disaster areaune rà ©plique  - after-shock, counter-attackla retraite  - retirementsalir  - to soil, tarnish, or smearun scrutin  - ballot, electionun sà ©isme  - earthquake, upheavalselon (prep) - according toun sinistrà ©, une sinistrà ©e  - disaster victimun soldat  - soldierun sondage  - pollle suicide assistà ©Ã‚  - assisted suicideun syndicat  - unionle systà ¨me de santà © publique  -  health care systemun tà ©moin  -  witnessune tempà ªte  -  stormle terrorisme  -  terrorismtirer (sur)  -  to shoot (at)les titres  - headlines, headline newsune tornade  - tornadoles transports en commun  - public transitun tremblement de terre  - earthquakeune trà ªve  - trucetuer  - to killun vaccin  - vaccineune victime  - victim (Note that this word is always feminine, ev en when referring to a man)voter  - to vote