Alkaline-earth Metal
A alkaline-earth metal is a chemical element second column of the periodic Tableau of the elements. This name comes from the term “metals of ground” used in Alchimie and describing metals which resist the fire (the Oxyde S of alkaline-earth metals not being affected by fire). The group of alkaline-earth metals, known as Group 2 (in the past IIA), includes/understands the Béryllium, the Magnésium, the Calcium, the Strontium, the Baryum and the Radium. The names of these elements come from their oxides, the alkaline grounds . The old terms indicating these oxides were béryllia (beryllium oxide), magnésia , strontia , baryta and quicklime (calcium oxide). “Alkaline-earth” designation is due to the fact that this group forms an intermediary between oxides of alkaline metals and oxides of Rare earths. The use of the “earthy” term to classify substances with inert appearance goes back to old times. The oldest known system is that of the ancient Greece, and consisted of a group of 4 traditional elements, including the ground. Philosophers and alchemists evolved/moved this model thereafter, that is to say Aristote, Paracelse, John Becher and George Stahl. In 1789, Antoine Lavoisier in his Elementary Traité of Chemistry , foot-note that these grounds was in fact of the chemical compounds. It called then them earthy salifiable simple substances . Thereafter it suggested that the alkaline grounds would be perhaps metal oxides, but it admitted that this was only one simple conjecture. In 1808, Humphry Davy continued the work of Lavoisier and was the first to obtain metal samples by electrolysis their grounds in fusion. These elements are characterized by a silver plated color, weak a Densité, large a Malléabilité, their easy reaction with the Halogène S to form a ionic salt, and with water (though this one is less easy than with the alkaline metals) to form strongly basic Hydroxyde S. For example, whereas the Sodium and the Potassium react with water to room temperature, magnesium reacts only with the steam and calcium with warm water. The elements of this group have two electrons on their electron shell most external and their electronic configuration most stable is done by the loss of two electrons to form a positive ion doubling charged.
Simple: Alkaline earth metal
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