Alkaline-Earth Metal

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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Alkaline-Earth Metal

any one of the chemical elements of the main subgroup of Group II of Mendeleev’s periodic system, comprising the calcium family: calcium, strontium, barium, and radium (beryllium and magnesium are also sometimes considered to be alkaline-earth metals). The origin of the name is related to the fact that the oxides of the alkaline-earth metals (”eerths” in alchemical terminology) were found to be alkaline in water. The outer electron shell of alkaline-earth metal atoms contains two 5 electrons; the preceding shell contains two s and six p electrons. The alkaline-earth metals exhibit an oxidation number of +2 in their compounds. They are chemically reactive, and their reactivity increases from calcium to radium. (See alsoCALCIUM; STRONTIUM; BARIUM; and RADIUM.)

References in periodicals archive ?

Alkaline and alkaline-earth metals compounds as catalysts for the methanolysis of sunflower oil.

Transesterification of used frying oil using calcium oxide as heterogeneous catalyst

Fluorides and chlorides of alkaline and alkaline-earth metals are used as additions, which enable improvement of various technological and metallurgical properties of the flux (Table 1), whereby one of the main requirements to fluxes for electroslag welding (ESW) and electroslag remelting (ESR) of titanium is complete absence of oxides, because presence in flux even in small amounts of such stable oxides as [Al.sub.2][O.sub.3], ZrO and Ti[O.sub.2] does not exclude possibility of titanium contamination by oxygen [2-3].

Electroslag melting of halogenide oxygen-free fluxes

The continental biosphere has greatly speeded up the rate of erosion of the surfaces of the continents and has given it special characteristics: increase in the pressure of CO2 in the soil and the addition of organic acids and speeding up the decomposition of silicates, all of which lead to the liberation of silica and alkaline-earth metals.