John Dalton And Atomic Theory

John Dalton And Atomic Theory John Dalton was the originator of atomic theory, which theory provided scientists with new ways of seeing the physical world. Atomic weights and fixed ratios of atoms inside compounds provided researchers with the knowledge to explore chemical compositions of matter. Daltons new information on atomic weights allowed a Russian chemist, Dmitry Mendeleyev, to create the periodic table of elements. This table provided the means for discovering new elements, and Dalton also proposed symbols for the elements. The symbols would represent the atom combination in compounds, but these were later changed to the abbreviations known today. Daltons theory had been accepted at the time, but it opened new questions about atom interactions. The structure and interaction of atoms refined atomic theory. Until Dalton, the line between physics and chemistry was almost unnoticeable, but his atomic theory distinguished and divided the two disciplines. In physics and chemistry, the atom is a cornerstone providing an understanding of matter and force, especially in quantitative analysis. Quantitative analysis refers to the measurement of how much of a certain substance is within a sample. Daltons theory was the beginning of nuclear energy and fusion research still used today. The theory also provides for the study of the quantitative relationships between substances in chemical reactions, or stoichiometry. It provides for structural theory and arrangements of atoms for influencing properties. Daltons models eventually turned into the understanding of 3-dimensional qualities of molecules and the affect of structure on properties. Daltons theory did have some inaccuracies, but it did provide the foundation for future generations of scientists. Atomic theory is the idea that matter is made u p of little units called atoms. In 1897, the British scientist J.J. Thomson discovered that atoms are in fact made up of smaller particles. Today atomic theory refers to matter being made up of units that are indivisible only some of the time. Dalton concluded that evaporated water exists in air as an independent gas. He wondered how water and air could occupy the same space at the same time, when obviously solid bodies cant. If the water and air were composed of discrete particles, Dalton reasoned, evaporation might be viewed as a mixing of water particles with air particles. He performed a series of experiments on mixtures of gases to determine what effect properties of the individual gases had on the properties of the mixture as a whole. While trying to explain the results of those experiments, Dalton developed the hypothesis that the sizes of the particles making up different gases must be different. John Dalton published the first table on relative atomic weights that included six elements viz. hydrogen, oxygen, carbon, nitrogen, phosphorous and sulfur. He stated the atomic weight of hydrogen to be 1. It was not confirmed as to how he derived the atomic weights. However, his laboratory notebook indicated that he found out the relative weights from the studies of the compounds water, carbon dioxide and ammonia. In his notebook, the elements were represented by symbols. He was the first person to propose the idea of identifying an element by its symbol. Later on, elements are represented by their abbreviations, for example, H is the abbreviation of the element hydrogen. While the concept of atoms was thus being made indispensable, the ancient belief that they were probably structure less and certainly indestructible came under devastating attack. J.J. Thomsons discovery of the electron in 1897 soon led to the realization that the mass of an atom largely resides in a positively charged part, electrically neutralized by a cloud of much lighter electrons. A f ew years later Ernest Rutherford and Frederick Soddy showed how the emission of alpha and beta particles from radioactive elements causes them to be transformed into elements of different chemical properties. By 1913, with Rutherford as the leading figure, the foundations of the modern theory of atomic structure were laid. It was determined that a small, massive nucleus carries all the positive charge whose magnitude, expressed as a multiple of the fundamental charge of the proton, is the atomic number. An equal number of electrons carrying a negative charge numerically equal to that of the proton form a cloud whose diameter is several thousand times that of the nucleus around which they swarm. The atomic number determines the chemical properties of the atom, and in alpha decay a helium nucleus, whose atomic number is 2, is emitted from the radioactive nucleus, leaving one whose atomic number is reduced by 2. In beta decay the nucleus in effect gains one positive charge by emitting a negative electron and thus has its atomic number increased by unity. Rutherfords gold foil experiment, performed in conjunction with Geiger and Marsden, provided evidence for the nucleus due to the scattering of alpha particles. The protons. Further work by Chadwick revealed the existence of neutrons within the nucleus of the atom. The atomic number describes the number of protons in the nucleus. For a neutral atom this is also the number of electrons outside the nucleus. Subtracting the atomic number from the atomic mass number gives the number of neutrons in the nucleus. Isotopes are atoms of the same element they have the same number of protons, or the same atomic number which have a different number of neutrons in the nucleus. Isotopes of an element have similar chemical properties. Radioactive isotopes are called radioisotopes. Most of the elements in the periodic table have several isotopes, found in varying proportions for any given element. The average atomic mass of an el ement takes into account the relative proportions of its isotopes found in nature. A nuclear binding force holds the nucleus of the atom together. The nuclear mass defect, a slightly lower mass of the nucleus compared to the sum of the masses of its constituent matter, is due to the nuclear binding energy holding the nucleus together. The mass defect can be used to calculate the nuclear binding energy, with E = mc2. The average binding energy per nucleon is a measure of nuclear stability. The higher the average binding energy, the more stable the nucleus. The basic difference between Rutherfords Atomic Theory and the Plum Pudding Model has to do with the fact that the Plum Pudding Model theorized that an atom was made up electrons the plums surrounded by a positively charged mass the pudding. Rutherford later proved that this wasnt the case and theorized that atoms were comprised of a very small nucleus surrounded by electrons. The basic tenets of that statement are still held to be true in the modern era. The chief difference is the fact that Niels Bohr, when theorizing the design of the atom, included a thesis for the forces that help to hold the atomic structure together. The Bohr model is still widely accepted by contemporary scientists. The Bohr model of the atom was established in 1913 as the leading theory of atomic structure. Because of this, it can be truthfully said that Rutherfords Atomic Theory was an extremely short-lived phenomenon. Despite its brief time frame, however, Rutherfords theory was extremely important because Niels Bohr wouldnt have been able to develop his own model without the established background that Rutherfords Atomic Theory laid out for him. www.angelfire.com/sc2/atomtheory/ www.iun.edu/~cpanhd/C101webnotes//dalton.html www.angelfire.com/sc2/atomtheory/ www.chemprofessor.com/atomic.htm www.nobeliefs.com/atom.htm www.chemlin.net/chemistry/atomic_theory.htm

Comparing Poe and Whittman Essay -- comparison compare contrast essays

Comparing Poe and Whittman  Ã‚     Ã‚   A successful writer is he who is able to transmit ideas, emotions, and wisdom on to his readers. He is cable of stirring emotions and capturing the reader's attention with vivid descriptions and clever dialogues. The writer can even play with the meanings of words and fuse reality with fiction to achieve his goal of taking the reader on a wonderful journey. His tools are but words, yet the art of writing is found in the use of the language to create though-provoking pieces that defy the changing times. Between the lines, voices and images emerge. Not everyone can write effectively and invoke these voices. It is those few who can create certain psychological effects on the reader who can seize him (or her) with inspiring teachings, frightening thoughts, and playful games with the language. These people are true writers†¦ In addition, authors frequently lack originality and simply take the reader on all-too-familiar voyages into politics, morals, or religion. Successful writers are those who risk and go on to write about topics that many times others have been less willing to address. The product of these extraordinary efforts is compositions richly enhanced by human feelings and real problems that we encounter and relate to our everyday lives†¦thought-provoking discussions about religion, philosophy, or politics. These pioneering authors are not afraid to write about evil, the perverse aspects of man, or even sexuality†¦Ã‚   Their true voices have risen from behind the words taking shape in the minds of the readers. Few have done this, but in the 19th Century two remarkable Americans produced compositions of unequal quality. Their styles and the way they approach the reader are different from t... ... something (AL 2139) Could it be that their originality sprouts from the fact that they have both been able to express so humanly the cries of the soul while at the same time leaving mysteries and ambiguity for the readers' minds to personalize to their own life experiences? Their distinct styles enabled them to expresses exactly what was on their minds with words, leaving behind all inhibitions. The themes of their compositions and the moral issues captured our attention. I think the reader was able to "feel" he was truly experiencing the story simply because so much was left as a mystery for our unconscious to reflect upon†¦ I am convinced that this is the key element that makes both Whitman and Poe successful writers.  Ã‚   Works Cited Reidhead J. ed.   (1998, Fifth Edition) The Norton Anthology of American Literature Volume 1: Norton & Company, New York

Adolescents and Cyberspace Essay

Abstract The Internet has a great deal of benefit in our lives. It is the window that opens onto the world and shows us everything that is happening around us. Although it is meant to help and support our needs, enrich our social lives and expand our civic connections, it has not been going so far in this way. A lot of research is showing that the heavy use of cyberspace is isolating people form the world around them. Knowing that adolescents are spending a great deal of their time in cyberspace, this article will examine the things they miss when they are left to grow up in it. Leaving Adolescents Grow Up in Cyberspace The question on whether leaving adolescents grow up in cyberspace is beneficial or not has long been controversial. When a lot agree that cyberspace has made their life easier, many others believe the opposite. Everything has side effects, which might have great impact on its user if not handled properly. It seems that adolescents, out of all other people, all missing a lot when their parents are letting them grow up in cyberspace. Everything in this advanced world is possible these days, that’s why we find students who study on the Internet in hybrid or online courses. Traditionally, learning has been assumed to take place in a classroom or face-to-face environment where the instructor and students are physically together, but not all students learn the same way and therefore the traditional approach is not ideal for all students (Young, 2007). This is true, but a lot of students are finding it difficult to cope with the new and modern way of learning, where the instructor lectures them online. Some students say: -â€Å"Instructor feedback tend to be slow† -â€Å"I didn’t feel as part of the class† -â€Å"You can’t verbalize your thoughts and let others hear your ideas† -â€Å"Too many technical problems† -â€Å"Unreliable Internet connections from my Internet service provider† -â€Å"You also lose the personal teacher student relationship† -â€Å"No way to read body language† -â€Å"With on-line classes, it is hard to be able to get the whole â€Å"personal† thing† -â€Å"You don’t get to see the professor or class members face-to-face† -â€Å"It takes more time to e-mail or post a question on the discussion board and wait for a response† (â€Å"Students’ Positive and Negative Experience in Hybrid and Online Classes†, 2007, page). Moreover, Irvine(2004) states: â€Å"Assignments are dispersed online. Students are much more likely to do research online than use a library. And even class handouts have gone the way of the Web, posted on electronic bulletin boards for downloading after class†(p.31A). So, if the Internet connection went off, students wouldn’t be able to continue their work. When the computer server in Emory University went down for a few hours one evening, a lot of people were at loose ends, they couldn’t to their homework (Sridharan, 2004). This is how adolescents are missing the more active and efficient way of learning because of cyberspace, thus suffering from a lot of educational and studying problems they are better off without. Looking at the world today would make us realize how much we miss security. And since adolescents are widely using cyberspace, they are the most likely to get affected by what it generates. A lot of teenagers have no problem in making friends, of whom they’ve never seen. In fact, they see that it is one of the purposes of using the Internet. But they never realize how dangerous it could be to meet someone you haven’t actually seen. The Internet allows people to communicate with people who are different from them, people in another country or kids at school they don’t talk to. This access of information is so easy, but of course there is a dark side to having such broad access: it gives identity thieves and sexual predators a new place to look for victims (Stern, 2004). Also, the Internet has shaped the way adolescents work, live, and relax. It has even created new ways for them to express themselves which might be liberating and fun but can also become a forum for of pettiness and criminal exploitation (Irvine, 2004). Furthermore, Ian and Walder (2005) say: As we have become dependent on the Internet, as the network of networks, so we have become vulnerable to criminal and terrorist networks that use cyberspace as a means to undermine and circumvent state control. Protecting against those that wish to attack  the integrity, confidentiality and availability of systems and data they process, is primarily an issue of implementing appropriate security measures. (page) The main purpose for this worry is because adolescents are unaware of what criminals might do to take advantage of people who want to be friendly, allowing them to threaten the country’s and society’s safety. In this way letting them spend too much time in cyberspace is making them loose a lot of security which puts them in dangerous problems later on. We must not forget the most important consequence of growing up in cyberspace: lack of social life and relationships. Sitting in front of the monitor for several continuous hours, without even noticing how time flies by quickly, makes us never want to get off the chair. As many adolescents are living in virtual communities, their only concern is making friends online. Ten years ago, social theorists were suggesting that the Internet would revolutionize social relationships (Carter & Denise M., 2004). Now, the Internet has come a far distance that kids and teens can’t live without it; people can find a job without leaving their desks, shop online without going to the mall and communicate with others without meeting face-to-face by e-mails, online chat rooms and instant messages. So, all the activities that were done with family and friends, are being done alone on the Internet. As a result, such activities have proved to be more isolating than watching television, which friends and family often do in groups, and the time spent with them is decreasing a lot in the presence of the Web. In addition, teens are preferring not to go out for walks or hang out with friends because they are busy in their own larger world. Know it or not, youngsters who are allowing time online to replace face-to-face interaction are being isolated from the real world and are being trapped in the virtual world (Staples, 2004). Seemingly, â€Å"Teenagers who spend much of their lives hunched over computer screens miss the socializing, the real world experience that would allow them to leave adolescence behind and grow into adulthood. These vital experiences, like much else, are simply not available in a virtual form† (Staples, 2004, p.A29). All of this is breaking the social relationships and is bringing up adults that don’t know how to deal with others because they never had the chance to sit and talk face-to-face. A lot of people fear of not being able to go with the flow; who ever doesn’t have access to cyberspace doesn’t have a life. But this isn’t proved to be completely true since it’s not being used in the best and efficient way. Of course it’s the parents job to lead them to the right track; they should always keep them under high supervision. To be more specific, parents should encourage them to have a real life, make real friends, go to real places and spend quality time with family. This doesn’t mean getting rid of this great technology but not letting it control them. Indeed, adolescents are missing a lot of the real world and its content, and aren’t aware of the circumstances and the costs of growing up in cyberspace. References Carter & Denise, M.(2004, December).Living in Virtual Communities: Making Friends Online.Journal of Urban Technology 11(3), 109-125.Retrieved March 19, 2008, from EBSCO Host database. El Mansour, B. & Mupinga, D.M.(2007, March).Students’ Positive and Negative Experiences in Hybrid and Online Classes.College Student Journal 41(1), 242-248.Retrieved March 19, 2008, from EBSCO Host database. Ian & Walder.(2005, April).Crime and Security in Cyberspace.Cambridge Review of International Affairs 11(3), 109-125.Retrieved March 19, 2008, from EBSCO Host database. Irvine, M.(2004, December 5).Youths Adopt, Drive Technology Advances.Fort Worth Star-Telegram, p.31A. Staples, B.(2004, May 29).What Adolescents Miss When We Let Them Grow Up in Cyberspace.New York Times, p.A24.

Use Of Language And Context Voltaire s Candide Essay

The narrative techniques, features of language and context Voltaire used when writing Candide tells us a lot about this book and what Voltaire was trying to achieve in writing it. Candide is told by a third person narrator who is not a main character in the book and is completely outside of the storyline. The title page of Candide implies that the book was found and translated by Doctor Ralph who is our narrator. This is a fiction created by Voltaire to distance himself from the book and to help the reader to understand the satirical nature of Candide. Telling the story from a third person perspective allows the narrator to know all the thing the characters in the book do not. He is omniscience, knowing everything about the circumstances and the characters without being involved with them. This approach works particularly well in Candide. It allows the reader to stand back and see how disturbing the word Voltaire has created is. It also gives the reader space to understand Voltaire’s purpose in writing Candide without getting too caught up in the plight of its characters. It also really highlights how naà ¯ve and almost narrow minded Candide is as a character, especially where his philosophical beliefs are concerned. The use of the third person narrator really highlights the more unrealistic moments in the passage, for example: â€Å"Candide, having served with the Bulgars, performed the Bulgar drill before the general of this little force with such grace, such celerity,Show MoreRelatedLiterary Criticism : The Free Encyclopedia 7351 Words   |  30 Pagesformal, topical, and thematic features.[7] The term coming-of-age novel is sometimes used interchangeably with Bildungsroman, but its use is usually wider and less technical. The birth of the Bildungsroman is normally dated to the publication of Wilhelm Meister s Apprenticeship by Johann Wolfgang Goethe in 1795–96,[8] or, sometimes, to Christoph Martin Wieland s Geschichte des Agathon of 1767.[9] Although the Bildungsroman arose in Germany, it has had extensive influence first in Europe and laterRead MoreWhat Does Organizational Change Mean?17842 Words   |  72 PagesLatour contends that ignorance of key concepts in scientific analysis is commonplace: We know very little about what causes sciences, technologies, organizations and economies. Open books on social science and epistemology, and you will see how they use the adjectives and adverbs ‘abstract’, ‘rational’, ‘systematic’, ‘universal’, ‘total’, ‘complex’. Look for the ones that try to explain the nouns ‘abstraction’, ‘rationality’, ‘systems’, ‘universe’, ‘science’, ‘organization’, ‘totality’, ‘complexity’