* Moseley observed and measured the X-ray spectra of various chemical elements obtained by diffraction in crystals. * The Moseley’s law. * Periodic Table. * Early X-ray crystallography * development of early X-ray spectrometry equipment * Moseley’s discoveries resulted in a more accurate positioning of elements in the Periodic Table by closer determination of atomic numbers. * He observed and measured the X-ray spectra of various chemical elements obtained by diffraction in
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suggested that the game was first developed by British military officers in India or South Africa who brought it back with them. A row of books were stood up along the center of the table as a net‚ two more books served as rackets and were used to continuously hit a golf-ball from one end of the table to the other. Alternatively table tennis was played with paddles made of cigar box lids and balls made of champagne corks. The popularity of the game led game manufacturers to sell equipment commercially. Early
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Table tennis is a sport in which two or four players hit a lightweight ball back and forth using table tennis rackets. The game takes place on a hard table divided by a net. Except for the initial serve‚ players must allow a ball played toward them only one bounce on their side of the table and must return it so that it bounces on the opposite side. Points are scored when a player fails to return the ball within the rules. Play is fast and demands quick reactions. Spinning the ball alters its trajectory
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Boron On the Periodic Table The chosen element was “Boron”. Its atomic number on the periodic table is 5. It has 5 protons/electrons and 6 neutrons. The scientific symbol for Boron is “B”. It is not a gas element; it is in between a metal and a non-metal‚ which they would call a metalloid or a semimetal. At room temperature‚ this element is a solid. The density is 2.34 g/cm3. When it is at room temperature‚ it is a poor electric conductor‚ but when it is at high temperatures‚ it is a good
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p electrons fill sequentially • A horizontal row on the periodic table is called a period. Elements in the same period have the same number of occupied energy levels. http://www.oakland.k12.mi.us/Portals/0/Learning/PeriodicTable.pdfThe electrons in the partially filled outermost shell (or shells) determine the chemical properties of the atom; it is called the valence shell. Periods 1‚ 2‚ & 3 The first three rows of the periodic table‚ called periods 1‚ 2 and 3‚ corresponding to the n=1‚ n=2
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series describing the relative reactivity of the metals being tested. The elements within a periodic table often show different trends in physical and chemical properties depending on the period or group they are apart of. In a periodic table‚ elements are arranged by increasing atomic number in horizontal rows called periods. The atomic numbers represent the number of protons in each element. The periodic table is also arranged such that elements with similar properties are in vertical columns known
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rearrange the chart above so that the elements appear in order of their atomic number and as they appear on the periodic table. Atomic NumberElement SymbolElement NameNumber of ProtonsNumber of Electrons Mass NumberNumber of NeutronsElectron Configuration 123456789101112131415161718 ArArgon181840222‚ 8‚ 8 b) What pattern do you see in the number of electrons moving across the periodic table? 3a) Lithium and sodium both behave similarly in chemical reactions. How many electrons do these elements
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The Tables TurnedWilliam Wordsworth’s stanzaic poem The Tables Turned (1798)‚ expresses his belief that true knowledge is learned through and by nature‚ not by reading books. Wordsworth uses his friendly relationship with the reader to convince them to quit their books and go out into the world and discover what it has to offer. Wordsworth’s welcoming relationship with the reader‚ his ongoing petitioning‚ and his assurance of true knowledge leaves the reader with a sense of his insight. William
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Periodic Table Trends: Atomic Radius - half of the distance between the centers of two atoms that are touching each other decreases moving left to right increases moving top to bottom Ionization Energy - energy required to remove an electron increases moving left to right decreases moving top to bottom Electron Affinity - ability to accept an electron alkaline earth elements have low electron affinities halogens have high electron affinities noble gases have electron affinities near zero
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Adopt an Element Purpose To research two elements on the periodic table and create a neat‚ colorful‚ and creative 8.5’ x 11’ poster on colored paper that highlights the following information: • Symbol (lettering must be 11 cm high‚ minimum must be placed in the left hand corner) • Name of element (lettering must be 2 cm high‚ minimum Must be underneath the symbol.) • Atomic number (lettering must be 2 cm high‚ minimum Must be placed in the top right hand corner) •
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