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 ?
The electrostatic potential distribution results reveal that a single metal atom (including alkali metal Li, Na, K, and transition metal Sc) doped at the top of phenyls within the TBPS building block can easily lose its valence elections and can be positively charged.
"I've been working with alkali metals for 50 years.
Typical alkalizing agents that have been used for quite some time in cancer therapy include salts of the alkali metals. The alkali metals are those elements found in the left-hand column of the periodic table, including lithium, sodium, potassium, rubidium and cesium, in descending order.
The alkali metals like Li, Na, K, Rb and Cs are observed to show a sharp transition from opaque to transparent at the characteristic ultraviolet wavelengths according to the following table:
"In the PFR, for instance, we are cleaning out the alkali metals and have had to think of special solutions such as remote handling tools on the hoof.
* Potassium, like all alkali metals, is soft and is a good conductor of heat and electricity.
Cation-water interactions: the [M.sup.+][([H.sub.2]O).sub.n] clusters for alkali metals, M = Li, Na, K, Rb, and Cs.
Following the periodic table, the book begins with alkali metals and earth metals and continues through transition elements, metallics, metalloids, nonmetals, halogens, and noble gases.
In order to meet its diesel goal, Honda said it has patented a new emissions technology in which exhaust flows through a plasma reactor that separates nitrogen oxides (N[O.sub.x]) and forms nitrogen dioxide that is then reduced or absorbed by alkali metals and silver.
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