The alkaline earth metals are a group of chemical elements in the periodic table with very similar properties. They are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure and readily lose their two outermost electrons to form cations with charge 2+ and an oxidation state, or oxidation number of +2. In the modern IUPAC nomenclature, the alkaline earth metals comprise the group 2 elements.
The alkaline earth metals are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). This group lies in the s-block of the periodic table as all alkaline earth metals have their outermost electron in an s-orbital.
All the discovered alkaline earth metals occur in nature. Experiments have been conducted to attempt the synthesis of element 120, which is likely to be the next member of the group, but they have all met with failure. However, element 120 may not be an alkaline earth metal due to relativistic effects, which are predicted to have a large influence on the chemical properties of superheavy elements.