Living Reference Work Entry

Encyclopedia of Geochemistry

Part of the series Encyclopedia of Earth Sciences Series pp 1-4

Date: Latest Version

Alkali and Alkaline Earth Metals

  • Ricardo ArevaloJr.Affiliated withPlanetary Environments Lab, NASA Goddard Space Flight Center Email author 


The alkali and alkaline earth metals comprise the first two columns of the periodic table, traditionally referred to as Groups IA and IIA, respectively (Figure 1). Although H is technically considered a member of Group IA, it is not an alkali metal like the rest of the elements in this column; rather, H is a highly volatile non-metal and the smallest and lightest atom of them all. From lithium (Li) through francium (Fr) in Group IA, and beryllium (Be) through radium (Ra) in Group IIA, the rest of the alkali and alkaline earth metals share a number of physical characteristics, such as: malleability, ductility, electrical/thermal conductivity, and reactivity at standard temperature and pressure. Although often associated with biological systems and dietary supplements, alkali and alkaline earth metals represent an extraordinarily important and versatile suite of elements that can be applied as geochemical tracers for a multitude of planetary processes. Moreover, many of these ...

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