Bohr Model of the Atom - Overview and Examples

Bohr Model of the Atom s The Bohr Model has an atom consisting of a small, positively-charged nucleus orbited by negatively-charged electrons. Heres a closer look at the Bohr Model, which is sometimes called the Rutherford-Bohr Model. Overview of the Bohr Model Niels Bohr proposed the Bohr Model of the Atom in 1915. Because the Bohr Model is a modification of the earlier Rutherford Model, some people call Bohrs Model the Rutherford-Bohr Model. The modern model of the atom is based on quantum mechanics. The Bohr Model contains some errors, but it is important because it describes most of the accepted features of atomic theory without all of the high-level math of the modern version. Unlike earlier models, the Bohr Model explains the Rydberg formula for the spectral emission lines of atomic hydrogen. The Bohr Model is a planetary model in which the negatively-charged electrons orbit a small, positively-charged nucleus similar to the planets orbiting the Sun (except that the orbits are not planar). The gravitational force of the solar system is mathematically akin to the Coulomb (electrical) force between the positively-charged nucleus and the negatively-charged electrons. Main Points of the Bohr Model Electrons orbit the nucleus in orbits that have a set size and energy.The energy of the orbit is related to its size. The lowest energy is found in the smallest orbit.Radiation is absorbed or emitted when an electron moves from one orbit to another. Bohr Model of Hydrogen The simplest example of the Bohr Model is for the hydrogen atom (Z 1) or for a hydrogen-like ion (Z 1), in which a negatively-charged electron orbits a small positively-charged nucleus. Electromagnetic energy will be absorbed or emitted if an electron moves from one orbit to another. Only certain electron orbits are permitted. The radius of the possible orbits increases as n2, where n is the principal quantum number. The 3 → 2 transition produces the first line of the Balmer series. For hydrogen (Z 1) this produces a photon having wavelength 656 nm (red light). Bohr Model for Heavier Atoms Heavier atoms contain more protons in the nucleus than the hydrogen atom. More electrons were required to cancel out the positive charge of all of these protons. Bohr believed each electron orbit could only hold a set number of electrons. Once the level was full, additional electrons would be bumped up to the next level. Thus, the Bohr model for heavier atoms described electron shells. The model explained some of the atomic properties of heavier atoms, which had never been reproduced before. For example, the shell model explained why atoms got smaller moving across a period (row) of the periodic table, even though they had more protons and electrons. It also explained why the noble gases were inert and why atoms on the left side of the periodic table attract electrons, while those on the right side lose them. However, the model assumed electrons in the shells didnt interact with each other and couldnt explain why electrons seemed to stack in an irregular manner. Problems with the Bohr Model It violates the Heisenberg Uncertainty Principle because it considers electrons to have both a known radius and orbit.The Bohr Model provides an incorrect value for the ground state orbital angular momentum.It makes poor predictions regarding the spectra of larger atoms.It does not predict the relative intensities of spectral lines.The Bohr Model does not explain fine structure and hyperfine structure in spectral lines.It does not explain the Zeeman Effect. Refinements and Improvements to the Bohr Model The most prominent refinement to the Bohr model was the Sommerfeld model, which is sometimes called the Bohr-Sommerfeld model. In this model, electrons travel in elliptical orbits around the nucleus rather than in circular orbits. The Sommerfeld model was better at explaining atomic spectral effects, such the Stark effect in spectral line splitting. However, the model couldnt accommodate the magnetic quantum number. Ultimately, the Bohr model and models based upon it were replaced Wolfgang Paulis model based on quantum mechanics in 1925. That model was improved to produce the modern model, introduced by Erwin Schrodinger in 1926. Today, the behavior of the hydrogen atom is explained using wave mechanics to describe atomic orbitals. Sources Lakhtakia, Akhlesh; Salpeter, Edwin E. (1996). Models and Modelers of Hydrogen. American Journal of Physics. 65 (9): 933. Bibcode:1997AmJPh..65..933L. doi:10.1119/1.18691Linus Carl Pauling (1970). Chapter 5-1.  General Chemistry  (3rd ed.). San Francisco: W.H. Freeman Co. ISBN 0-486-65622-5.Niels Bohr (1913). On the Constitution of Atoms and Molecules, Part I (PDF). Philosophical Magazine. 26 (151): 1–24. doi:10.1080/14786441308634955Niels Bohr (1914). The spectra of helium and hydrogen. Nature. 92 (2295): 231–232. doi:10.1038/092231d0

The Admissions Process at Liberty University

The Admissions Process at Liberty University Liberty University is generally a selective school, but this is due to the large applicant pool. Only around a quarter of applicants are admitted. Students will, in general, need strong grades and high test scores to be admitted to Liberty. Application requirements include an application form, SAT or ACT scores, high school transcripts, and a personal essay. For more information, feel free to contact the admissions office. Admissions Data Liberty University Acceptance Rate: 24%GPA, SAT and ACT Graph for Liberty AdmissionsTest Scores: 25th/75th PercentileSAT Critical Reading: 480/600SAT Math: 470/ 90SAT Writing: - / -ACT Composite: 21/28ACT English: 2/28ACT Math: 19/27 Liberty University Description Founded by Jerry Falwell and grounded in evangelical Christian values, Liberty University takes pride in being the worlds largest Christian university. The residential campus of about 12,000 students is located in Lynchburg, Virginia. The university enrolls another 50,000 online and has set a goal to increase that number significantly in the future. Students come from all 50 states and 70 countries. Undergraduates can choose from 135 areas of study. Liberty has a 23 to 1Â  student/faculty ratio. All faculty are non-tenured. Liberty is not for everyone. This Christ-centered school embraces political conservatism, prohibits alcohol and tobacco use, requires chapel three times weekly, and enforces a modest dress code and curfew. The university is a common speaking venue for conservative political candidates. In athletics, the Liberty University Flames compete in the NCAA Division IÂ  Big South Conference. The school fields 20 varsity teams. Enrollment Total enrollment in 2016: 75,756Â  (47,050Â  undergraduates)Gender breakdown: 42% Male / 58% Female58% Full-time Costs Tuition and fees (2016-2017): $21,292Books: $1,771Room and board: $8,963Other expenses: $5,619Total cost: $37,645 Financial Aid Percentage of new students receiving ad (2015-2016): 96%Percentage of new students receiving aidGrants: 95%Loans: 57%Average amount of aidGrants: $10,768Loans: $7,005 Academic Programs Most popular majors:Â  Accounting, Business, Criminal Justice, Interdisciplinary Studies, Nursing, Psychology, Religion Transfer, Graduation, and Retention Rates First-year student retention (full-time students): 83%Transfer out rate: 21%4-Year Graduation rate: 32%6-Year Graduation rate: 54% Intercollegiate Athletic Programs Mens Sports:Â  football, tennis, track and field, baseball, cross country, basketball, golf, soccerWomens Sports:Â  basketball, field hockey, volleyball, cross country, lacrosse, softball, soccer, swimming and diving, track and field Source Liberty University. National Center for Education Statistics, U.S. Department of Education, 2018.

The Inuit in the Age of Globalization Essay Example | Topics and Well Written Essays - 500 words

The Inuit in the Age of Globalization - Essay Example This essay researches the modern lifestyle of Inuit tribes. A lifestyle that has been profoundly affected by the process of globalization. Relatively healthy from their lives as subsistence hunters and gatherers of the sparse Arctic tundra, the Inuit were completely self-sufficient until they first came into contact with Europeans in the 19th century. By the late 1880s, the Inuit Eskimos were already strongly affected by the same sorts of ‘white man’s diseases’ that had affected more southern tribes, such as measles and smallpox, brought in by traders and whaling ships. At the same time, however, the Inuit have been able to gain increased access to medical care, making it possible for the population to restore itself following initial introduction. This essay also describes significant economic changes that were brought about, both for the good and the detriment of the indigenous people. Positive changes included the introduction of metal, which could be used for everything from knives to fish hooks and increased the Inuit’s ability to catch food for their villages. Negative changes included the over-fishing of their waters, making it increasingly difficult for them to continue competing for their necessary food with outsiders who were better equipped with new technologies. Increasingly, Inuits are turning to money and store-bought items as preferable alternatives to the traditional hand-made products once relied upon. Author of this essay also covered climate change topic and the way in which the Inuit live through the actions of other countries.

Strategy and specific requirements for the Asset Team members Coursework

Strategy and specific requirements for the Asset Team members - Coursework Example Again, the asset manager would ensure that project delivery is undertaken without a compromise to any acts that fall outside the stipulated scope and system definition. Based on all the issues outlined above, the mission statement for the asset team members will to â€Å"to deliver a globally competitive asset management standards that meet the demands of the project at both the asset in-flow and asset out-flow stages.† Task 2: Asset Manager and Asset Management Team Strategy and specific requirements for the Asset Team members The strategy for the asset team members would be doubted as â€Å"independent dynamism†. This strategy is made up of two major aspects, which are the need for asset team members to be independent in their decision making and the need for asset team members to be proactive and dynamic in their decision making. This perspective of strategy is adapted because of the generalized mission to ensure that the service delivery that should come from the as set management of the project would be a globalised one that can rightly compete with global models. To do this easily, the asset team members are each expected to possible a competence requirement of decisiveness, action driven, goal oriented and independent mindedness with an ability to work with minimal instruction. How the Asset Team members will be sourced The search for asset team members will be undertaken on a well rehearsed scale and according to a well coordinated pattern. Such an approach is expected to result in a situation whereby nothing but the best of human resource will be sourced for the project. To this end, there shall be a specialized recruitment and... The search for asset team members will be undertaken on a well rehearsed scale and according to a well coordinated pattern. Such an approach is expected to result in a situation whereby nothing but the best of human resource will be sourced for the project. To this end, there shall be a specialized recruitment and selection procedure that will take place on a peripheral level. What this means is that invitation for application for recruitment shall be extended to all potential members from within and without the company. This would ensure that as many talents as possible are sampled and that as much competition as possible exist among the applicants. Job specifications and requirements shall be spelt out and critically examined for each applicant. A team consultants and technocrats in the field of asset management would then undertake the final selection based on a teamed interview section for each of the applicants. What this means in the long run is that each person who becomes a m ember of the team would have to justify his or her inclusion in the team.

Television in the Modern Media System Essay Example | Topics and Well Written Essays - 1250 words

Television in the Modern Media System - Essay Example As a matter of fact, in this rapidly-evolving world where media has spread across the globe, issues that come with media’s operations should be extensively documented. Here, the point of your argumentative claim becomes relevant. Your type of support includes reason and emotion. Hence, in order to raise the persuasive ability of your article, the intensity of emotion and the clarity of reasoning need to be maximized. In fact, the actual body of the article contains some points worth discussion. The first statement of paragraph 10 is perhaps the most vivid expression of your stance. I would like to appreciate this since you made a clear claim about your argument here; you mentioned how media has become an omnipresent activity and parents are helpless when it comes to monitoring sexual exposure towards children. The benefit of this is that most readers are not fully attentive throughout the whole reading process, so the writing must possess simple straightforward expressions of your principle idea. If one fails to do that, the reader might not be able to understand your point of view and your idea might be camouflaged by wordy expressions and complex structuring. Therefore, it is highly critical to organize and outline the viewpoint, especially in argumentative essays (Writing Position Papers). Often, you have used research statistics and figures to support your claim. You have mentioned research findings of the American population, which is reasonable since your audience is American; however, there feels a slight insufficiency of supporting statistics in your writing. This is because when one writes about an issue concerning the whole society and people, regardless of demographics, there needs to be a substantial amount of information to notify the scale of the issue and also to support one’s claims.  

Focus of the Marketing Plan Essay Example for Free

Focus of the Marketing Plan Essay †¢Construct an overview of internal and external contingencies, describing at least two internal and three external contingencies and how they impact the sports marketing plan. †¢Justify market selection decisions including the psychological and sociological factors as influences. Include targeting and positioning of the product(s). †¢Generate a Sports Marketing Mix for your organization to address the promotion mix of advertising, public relations, sales promotion, and pricing. †¢Create a plan for the marketing process. Within that plan include a control phase and an implementation strategy. Any unique issues should also be addressed in this section, including the impact on facilities and any specific departments or segments of the organization impacted by the plan. Writing the Marketing Plan The Marketing Plan: †¢Must be eight to ten double-spaced pages in length and formatted according to APA style as outlined in the approved APA style guide. †¢Must include a cover page that includes: Student’s name Course name and number Title of paper Instructor’s name Date submitted †¢Must include an introductory paragraph with a succinct thesis statement. †¢Must address the topic of the paper with critical thought. †¢Must conclude with a restatement of the thesis and a conclusion paragraph. †¢Must use APA style as outlined in the approved APA style guide to document all sources. †¢Must include, on the final page, a Reference Page that is completed according to APA style as outlined in the approved APA style guide.

El Salvador :: essays research papers

El Salvadorian Representative at the United Nations   Ã‚  Ã‚  Ã‚  Ã‚  On Thursday March 3rd I had the fortune of yet again hearing another wonderful woman speak on behalf of her country. Unfortunately I was unable to get her name but I was able to write down some of her key thoughts. Like one of the other women she did not express a lot of views as to what was going on with the women in her country but she gave sound advice as to what needs to be done not only by the women in her country but every woman in any country who is fighting for the equality of women.   Ã‚  Ã‚  Ã‚  Ã‚  Before going into the things that she noted that needs to be done by the people, she said that the living condition in El Salvador for women was much worst than men. This is a sad but true statistic. She also went on to say that 40% of households are owned and maintained by women, however, the sad part is that women have a harder time maintaining their home because of the biases and the prejudices against women. This limits their ability to get jobs that are descent paying to take care of the family. As she said, women don’t have the positions that they should have and that they deserve.   Ã‚  Ã‚  Ã‚  Ã‚  One of the main things that she brought up and touched on was the fact that there is a lack of cooperation between the government and non-governmental organizations. It seems to be a wedge that is driving these two entities apart rather than bringing them together for a common good. It seems as if the NGO’s and the government are somewhat in a feud. The government is usually the one that does not want anything to do with the NGO’s; they may look at the work of the NGO as something that is less important than theirs. This is not so and the government needs to have a broader aspect of what NGO’s do and what they really promote. This woman stressed over and over again in her speech the link that needs to be drawn between these two things. The work of an NGO can in fact help and progress the work of the government and that is what people don’t seem to understand.   Ã‚  Ã‚  Ã‚  Ã‚  Another important point that I stood up to was when she said that the fact that people did not want to educate him or herself.