 | Term | Definition |
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Dmitri Mendeleev |
Russian chemist, discovered a pattern to the elements, 1869, arranged by increasing atomic mass, made the periodic table |
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Periodic |
describes something that occurs or repeats at regular intervals |
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Periodic Law |
the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements |
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Henry Moseley |
British scientist, determined the number of protons, atomic number, in an atom |
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Metals |
few electrons in the outer energy level, most are solid at room temperature |
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Properties of Metals |
shiny, ductile- can be drawn into thin wires, good conductors of electrical current and thermal energy, and malleable- can be flattened without being smashed |
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Nonmetals |
almost a complete set of electrons in the outer energy level, more than half are gases at room temperature |
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Properties of Nonmetals |
not malleable, not ductile, not shiny, poor conductors of thermal energy and electrical current |
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Metalloids |
also called semiconductors, about half of a set of electrons in their outer energy levels |
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Properties of metalloids |
shiny, brittle, hard, good conductors of electrical currents |
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Period |
a horizontal row of elements in the periodic table |
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Group |
a vertical row of elements in the periodic table, elements in group share chemical properties, also called a family |
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Copper |
Cu, Cuprum |
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Gold |
Au, Aurum |
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Iron |
Fe, Ferrum |
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Lead |
Pb, Plumbum |
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Tin |
Sn, Stannum |
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Mercury |
Hg, Hydrargyrum |
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Silver |
Ag. Argentum |
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Sodium |
Na, Natrium |
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Potassium |
K, Kalium |
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Antimony |
Sb, Stibnum |
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Tungsten |
W, Wolfram |
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Alkali metals |
Group 1, 1 electron in outer level, very reactive, soft, silver, shiny, low density; Lithium, Sodium, Potassium, Rubidium, Cesium, Francium |
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Alkali-earth metals |
Group 2, 2 electron in the outer energy level, very reactive but less reactive than alkali metals, silver, higher densities than alkali metals; Beryllium, Magnesium, Calcium, Strontium, Barium, Radium |
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Transition metals |
Groups 3-12, 1-2 electrons in the outer energy level, less reactive than alsali-earth metals, shiny, good conductor of thermal energy and electrical current, high density |
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Lanthanides |
in the 1st row of transition metals; shiny, and reactive metals |
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Actinides |
in the 2nd row of transition metals, radioactive, unstable, do not occur in nature |
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Boron Group |
3 electrons in the outer energy level, reactive, solids at room temperature; Boron, Aluminum, Gallium, Indium, Thallium |
