THE PERIODIC TABLE HISTORICAL BACKGROUND The idea that all things are elements or combinations of elements can be found in the writings of the ancient Greeks and other early peoples. Although this idea may seem simple‚ it is very difficult to decide if a substance is indeed an element or a compound. There were twelve chemical elements discovered in ancient times‚ but it was not known that they were elements. Another 76 elements were discovered between 1557 and 1925. Many mistakes were made in
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in the periodic table is being used in everyday life‚ it is also an essential element within your body. It is just another element‚ but one of the differences is that this element is something that most people consume every day. Sodium has played an important role in everyday life because of its uses in medicine‚ industry‚ and agriculture(Shriver). Sodium was discovered in 1807 by a man named Sir Humphrey Davy. He was well known for his discoveries of most alkali metals and Alkaline Earth Metals
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Periodic Table of the Elements I 1. 1 1 2 H H He II 1.00794 3 2. 4. 5. 6. Li Be 9.012182 IV V VI 1.00794 4.002602 5 6 7 8 9 10 N O F Ne B C 10.811 12.0107 13 14 15 Si P 12 Na Mg Al 22.989770 24.3050 26.981538 14.00674 15.9994 18.9984032 20.1797 16 28.0855 30.973761 17 18 S Cl Ar 32.066 35.4527 39.948 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Br Kr 39.0983
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The development of Periodic Table Elements such as gold and silver have been known since the earliest times. In 1649‚ a German alchemist‚ Hennig Brand made the first scientific discovery of an element‚ phosphorous. In the next 200 years‚ knowledge about the properties of elements and their compounds was gained. By 1869‚ 63 elements had been discovered in total. Scientists began to categorise those elements according to the similarities of their physical and chemical properties‚ which become the
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question and its answers may be split across a page break‚ so be sure that you have seen the entire question and all the answers before choosing an answer. 1. The two most well-known alkaline earth metals are A. calcium and magnesium. B. magnesium and barium. C. strontium and radium. D. calcium and barium. 2. Refer to the periodic table of elements (Figure 30 in your study unit) to help you answer
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lecture theatre that doesn’t contain a periodic table of the elements. It required the immense research and determination of the scientist Dmitri Mendeleev to show us that all elements followed a natural form and provided us with the first decent periodic table. There are 111 elements recognised today by IUPAC and they are arranged in the periodic table in horizontal groups and vertical periods. The eight groups consist of the alkali metals‚ the alkaline earth metals‚ the transition elements‚ metalloids
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with Electrons Have you ever wondered exactly how the elements on the periodic table are organized‚ what the groups on the periodic table mean‚ and how electrons work in an atom‚ compound‚ and chemical bond? The way elements are organized on a periodic table has to do with the characteristics that they hold. There are groups‚ periods‚ compound formation and color coordination in a periodic table. The periodic table is organized in many ways. As stated by Chem4kids.com‚ "Each element is placed
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tried grouping the three halogens elements (chlorine‚ bromine‚ and iodine) in a consecutive order of atomic weights. The idea of putting the elements together finally took shape when the two scientists‚ Dmitry Mendeleev and Julius Lothar Meyer successfully arranged the order of the elements by their atomic weight and discovered that the properties of the elements recur in the same pattern. With the works of these scientists‚ the periodic table was created as well as the periodic law. With this set‚ scientists
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DEVELOPMENT OF THE PERIODIC TABLE Although Dmitri Mendeleev is often considered the "father" of the periodic table‚ the work of many scientists contributed to its present form. Elements such as gold‚ silver‚ tin‚ copper‚ lead and mercury have been known since earliest times. In 1649 the first scientific discovery of an element occurred. Hennig Brand‚ a German chemist‚ treated urine to a series of processes that resulted in the production of the element phosphorus. Over the next 200 years
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Periodic Table The periodic table is a table‚ where all known chemical elements are arranged. They are organized on the basis of their atomic numbers‚ electrons and chemical properties. The atomic of an element is the same as the number of electrons or protons in that particular atom. They elements in the table are placed in order from the lowest to the highest. 429768018669000The periodic table is ordered into periods and groups. A row of elements across the periodic table is calleda a period
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