arranging the elements in ascending order of atomic weight and grouping them by similarity of properties. He predicted the existence and properties of new elements and pointed out accepted atomic weights that were in error. By arranging all of the 63 elements then known by their atomic weights‚ he managed to organize them into groups possessing similar properties. He constructed the tables by listing the elements in rows or columns in order of atomic weight and starting a new row or column when
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work of two young chemists‚ Brett Thornton and Shawn Burdette‚ whose 2010 article I have drawn heavily from. As in the case of many of the seven elements already surveyed‚ the view that Moseley’s experimental demonstration of the concept of atomic number resolved all issues in a categorical fashion is once again shown to be highly misleading. Early Claims for Element 85 The position of element 85 in the periodic table shows it to lie among the halogens. Not surprisingly‚ therefore‚ the early
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The effects of the atomic bomb were terrible. There’s no doubt in my mind that the atomic bombs dropped on Hiroshima and Nagasaki were a costly mistake. Atomic bombs produce heat millions of degrees high‚ and visible ultraviolet and inferred rays.(Lapp 844) Everyone and everything exposed to their blast is affected. No one is left untouched‚ whether it be emotional or physical; in many cases both. However‚ many members of the science community argue that the atomic bomb was a great advance in technology
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the atomic bombs. By doing this‚ there would be many benefits‚ but also some very harsh consequences. The atomic bombs were necessary to end the war because they allowed the US shut things down quickly‚ they assisted the US with showing it’s power‚ and it helped get justice for the soldiers that have already lost their lives fighting for their country. The main reason the US felt the need to drop the atomic bomb was because it was crucial for them to end this war once and for all. The atomic bombs
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Was the Atomic Bombing Justified? The Atomic Bomb made a very serious statement at a time when the world was in disarray (“Manhattan”). World War II was one of the most destructive times in history causing over 50 million deaths and leaving behind mental and physical casualties of war. (“World War II”) It started in September‚ 1939 when Germany invaded Poland and continued on a destructive path through Europe. Britain and France declared war on Germany. Two years prior in 1937‚ the Sino Japanese
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most awesome man‚ Karl Machin‚ lives in.) Technetium has 43 protons so its atomic number is 43. It has 55 neutrons. The sum of 55 and 43 is 98 because of that 98 is the mass number of Technetium. 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
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Dysprosium is a member to the lanthanide family on the periodic table just like all the other rare elements. Shown in Fig.1 is when dysprosium is places on the periodic table. It is a solid that is very soft‚ easily cut by a knife. Its atomic number is 66‚ atomic mass is 162.5 and Dy is its symbol. Dysprosium is soft enough to get cut with
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It has the atomic number twenty and the relative atomic mass of 40.078. The standard state of calcium‚ which means the reference point used to calculate the properties in different conditions‚ is solid at 298 K. This element is a silvery white and classified as metallic‚ which means
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(Each question carrys 2 marks) 11. An element E has following electronic configuration:K L M 2 8 6 a. To which group of the periodic table does element E belong? b. To which period of the periodic table does element E belong? c. State the number of valence electrons present in element E. d. State the valency of the element E. 12. What is Pollination? Describe Cross Pollination. 13. The organisms formed by asexual reproduction are considered as clones. Why? State the advantage of sexual
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popular. From TV tubes to Cryogenics to Neon signs to even lasers. Neon has been a vast element that can be used widely because of its unique chemical and physical properties. Neon has many interesting properties and they include: Neon’s atomic number is ten. It has an atomic mass of roughly 20.180. Represented with the symbol Ne. Neon is in group 18‚ period 2‚ and is one of the eight noble gases in the periodic table. It was discovered by Sir William Ramsay and Morris M. Travers in 1898 in London‚ England
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