alkali metals


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Related to alkali metals: Halogens

alkali metals,

metals found in Group 1 of the periodic tableperiodic table,
chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the table entitled
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. Compared to other metals they are soft and have low melting points and densities. Alkali metals are powerful reducing agents and form univalent compounds. All react violently with water, releasing hydrogen and forming hydroxides. They tarnish rapidly even in dry air. They are never found uncombined in nature. In order of increasing atomic number the alkali metals are lithiumlithium
[Gr.,=stone], metallic chemical element; symbol Li; at. no. 3; interval in which at. wt. ranges 6.938–6.997; m.p. about 180.54°C;; b.p. about 1,342°C;; sp. gr. .534 at 20°C;; valence +1. Lithium is a soft, silver-white metal.
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, sodiumsodium,
a metallic chemical element; symbol Na [Lat. natrium]; at. no. 11; at. wt. 22.98977; m.p. 97.81°C;; b.p. 892.9°C;; sp. gr. 0.971 at 20°C;; valence +1. Sodium is a soft, silver-white metal.
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, potassiumpotassium
, a metallic chemical element; symbol K [Lat. kalium=alkali]; at. no. 19; at. wt. 39.0983; m.p. 63.25°C;; b.p. 760°C;; sp. gr. .862 at 20°C;; valence +1.

Potassium is a soft, silver-white metal.
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, rubidiumrubidium
, metallic chemical element; symbol Rb; at. no. 37; at. wt. 85.4678; m.p. 38.89°C;; b.p. 686°C;; sp. gr. 1.53 at 20°C;; valence +1. Rubidium is a very soft silver-white metal.
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, cesiumcesium
[Lat.,=bluish gray], a metallic chemical element; symbol Cs; at. no. 55; at. wt. 132.90545; m.p. 28.4°C;; b.p. 669.3°C;; sp. gr. 1.873 at 20°C;; valence +1. Cesium is a ductile, soft-as-wax, silver-white metallic element. It is in Group 1 of the periodic table.
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, and franciumfrancium
[from France], radioactive chemical element; symbol Fr; at. no. 87; mass no. of most stable isotope 223; m.p. about 27°C; (estimated); b.p. 677°C; (estimated); sp. gr. unknown; valence +1.
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References in periodicals archive ?
Properties of a-M@n- acenes (M = Li, Na and K) salts (n = 1, 2 and 3) are together affected by adding the conjugated benzenoid rings and different alkali metal atoms with different losing electron feasibility and atomic radius, which also obviously increases 0 values when losing electron feasibility and atomic radius of alkali metals increase 0 values are increase correspondingly.
The remaining stockpile of 57 tonnes of NaK coolant comprises a volatile alloy of two alkali metals which would burst into flames upon exposure to the atmosphere.
The highly reactive alkali metal combines easily with other elements to form compounds.
The percentages of leached alkali metals are plotted in Fig.
Louis, MO-based life science and high technology company Sigma-Aldrich and New York, NY-based early advanced materials company SiGNa Chemistry recently announced that Sigma-Aldrich will distribute SiGNa's new technology for the controlled use of alkali metals, which has applications in such areas as hydrogen energy production for micro fuel cells.
Only hot amines and molten alkali metals affect the copolymer, and there is no known solvent for Halar under 250[degrees]F.
Alkali metals and chlorine present in fuels favor the formation of ash deposits and intensify the high-temperature corrosion and wear of boiler heat-transfer surfaces.
They can accumulate a large variety of elements, ranging from the heaviest of metals, such as lead or mercury, to the alkali metals, including radioisotopes such as caesium-137.
Shamovsky, a Grade 12 student at Holy Cross Catholic Secondary School in Kingston, ON won for his project "Cathodic Oxidation or: How Alkali Metals Attack Corundum".
Melt purification primarily consists of lowering the contents of alkali metals.
Specific topics considered include chlorine in one or more coals, alkali metals (e.