Since the ancient times‚ people like the Greeks were acknowledged of the existence of elements‚ but only knew of common ones like gold‚ tin‚ and copper. It wasn’t until the middle of the nineteenth century when about 50 elements were discovered and scientists began to wonder if the elements vary from each other or if a pattern is represented in the arrangement of the elements. A number of scientists tried different kinds of patterns. For example‚ the German scientist Johann Wolfgang Döbereiner tried
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Joy Jenkins Changing of the periodic table Today‚ the periodic table organizes the elements in horizontal rows‚ or periods‚ by order of increasing atomic number. The elements are also organized in vertical columns‚ or groups‚ based on similar physical characteristics and chemical behavior. I believe the periodic table will continue to evolve as new elements are discovered. One of the earliest attempts to organize the elements based on their chemical and physical properties was made by German
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It also involves choosing tasks that must be performed to attain organizational goals‚ outlining how the tasks must be performed‚ and indicating when they should be performed. Planning activity focuses on attaining goals. Managers outline exactly what organizations should do to be successful. Planning is concerned with the success of the organization in the short term as well as in the long term. Organizing deals with the development of an organizational structure to implement strategies. Organizing
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In American Literature‚ the period of the Puritans sticks out as a time with many great authors. Two‚ William Bradford and Reverend Jonathan Edwards are still studied today. Bradford was an author who wrote about the historical section of Puritan life‚ while Edwards was a great speaker who wrote sermons to give in front of his congregation. Although living in the same time period Reverend Jonathan Edwards and William Bradford used very different styles of writing. In writing‚ praise and
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Promethium‚ Pm‚ is the 61st element on the Periodic Table. It was discovered in 1945 by Jacob A. Marinsky. It’s a metal‚ and named after the Greek God Prometheus. It is not naturally occurring‚ but can survive outside of a lab. Promethium has an atomic number of 61‚ which is the number of protons. Its atomic mass‚ protons+neutrons‚ is 145u. It is an isotope. This means that it has a different number of neutrons (84) than the number of electrons and protons (61). Every element changes states
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It is in the d-block and it is a transition metal. Technetium is in the 7th group in the periodic table because it has 1 electron on its last shell. Also it is in the 5th period in the periodic table because it has 5 shells. Number of energy levels of Technetium is 5. Its electron shells are 2‚8‚18‚14‚1 as it is in the picture. Firstly‚ Russian chemist Dmitri Mendeleev‚ who is the creator of the periodic table‚ predicted Technetium’s existence. He called it eka-manganese because there was a missing
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Andrew Hom Chemistry CP O3.03 Periodic Trends Part I: Atomic Radius Trend Going Across the Periodic Table Part 2: Atomic Radius Trend Going Down A Group Part 3: Analysis and Conclusion After completing both graphs‚ answer the questions below in complete sentences. Both the question and your answer should be included in the document (along with the two graphs) that you submit to your instructor. 1) Refer to the graph that you created in Part 1 of this assignment. Describe the general
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Introduction: The periodic is a table of the elements‚ organized in order of increasing atomic number. Elements that have similar chemical properties and electronic structures appear in vertical columns‚ or also called groups. The Periodic Law states that when elements are placed in order of increasing atomic number‚ their physical and chemical properties display a periodic pattern. The purpose of the lab was to discover how two periodic properties‚ atomic radius‚ and first ionization energy‚ vary
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What is Cost & Management Accounting Reporting Systems? Cost Accounting Reporting System deals with the process of tracking‚ measuring‚ recording and classifying the appropriate allocation of expenditure (financial and non-financial) for the determination of the cost of product or service in an organization and for the presentation of suitably arranged data for the purpose of control and guidance of management (Horngren et al‚ 2010). Costs are measured in terms of Direct Costs‚ Indirect Costs and
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PERIODIC CLASSIFICATION OF ELEMENTS Introduction There are 115 elements that are known at present. Some elements have similar properties whereas some others have completely contrasting properties Scientists began to look for some pattern in the properties of these elements Dobereiner’s triads In 1817‚ Johann Wolfgang Dobereiner‚ a German chemist‚ classified elements into groups based on their properties. He kept all elements having similar properties in one group. Most of his groups had three
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