Abundance and Occurrence:- The alkali and alkaline earth metals are the most violently active of all the metals. These are readily oxidized and therefore, are not found in the free state in nature. These are found in the combined form with halide, sulphate, carbonate, silicate ions, etc.
The abundance of alkali and alkaline earth metals in the earth’s crust shows a good range. Among these, calcium is the fifth most abundant element in the earth’s crust and hence the third most abundant metal after aluminium and iron. Vast sedimentary deposits of CaCo3 occur over large parts of the earth’s surface. Magneshium is the sixth and sodium is the seventh most abundant element in the crustal rocks. These are fourth and fifth most abundant metals after Al, Fe and Ca. potassium is the nest most abundant element after sodium. There are unlimited supplies of NaCl in natural brines and oceanic waters. The occurrence of other metals in the earth’s crust is very poor. Francium and radium are radioactive and have rare terrestrial abundance. Beryllium is rare and radium is the rarest of all comprising only 10-10 percent of igneous rocks.