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12 Cards in this Set
- Front
- Back
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Dobreiner
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He organized the elements into triads- three elements that had similar properties. Like (Li, Na, K)
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Newlands
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He put the elements in increasing atomic mass. He found out that every 8th element had similar properties. He called this the law of Octaves, because of this, he wasn't taken seriously by other scientists.
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Mendeleev
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He based a lot of his work off of Newlands. He created the first periodic table. He put them in order of increasing mass, and he found out that there were repeating patterns. A repeating pattern is called periodic. When he put the periodic table together he grouped them with similar properties, even if the atomic mass said that it had to go somewhere else. Then he left some spaces where he predicted more elements will be discvoered.
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Mosely
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He worked with Rutherford anazlyzing metal spectra. He discovered that te elements fit better into the patterns if it was ordered INCREASING ATOMIC NUMBER (nuclear charge)
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Periodic Law
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the physical and chemical properties of he elements are periodic functions of heir atomic numbers
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Group 1: Alakali metals
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are soft enough to cut with a knife, have a silvery appereance, aren't found as free elements in nature, and react crzily to most nonmentals to produce hydrogen gas and alkali aqueous solutions.
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Group 2 Alakaline Earth metals
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harder, denser and stronger than alkali metals. Higher metling points. less reactive than alkali metals, but still too reactive to be found in nature.
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Transition metals
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d block elements. metals with metallic properties-good conductors of electricity, high luster. less reactive than alkali and alkaline erath metals.
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main group elements
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p block and s block
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nonmetals
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p block
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metalloids
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B Si Ge As Sb Te. brittle solids with some properties of metals and some of non metals.
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Group 17
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halogens. most reactive nonmentals. react vigorously with most metals to form salts.
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