Alkaline earth metal

Alkaline earth metal: The term used for the elements in Group IIA of the Periodic Table - Beryllium, Magnesium, Calcium, Strontium, Barium.

The alkaline earth metals are silvery colored, soft, low density metals, which react readily with halogens to form ionic salts, and with water, though not as rapidly as the alkali metals, to form strongly alkaline (basic) hydroxides. For example, where sodium and potassium react with water at room temperature, magnesium reacts only with steam and calcium with hot water. These elements all have two electrons in their outermost shell, so the energetically preferred state of achieving a filled electron shell is to lose two electrons to form a doubly charged positive ion.