Group 1 elements - the alkali metals

These elements have one electron in the outermost shell of their atoms their chemistry is dominated by the tendency to lose this electron and they are good reducing agents. The general ionic equation for this loss of an electron can be written as 

Most of the compounds of the alkali metals are therefore ionic, and the alkali metals have an oxidation state of +1 in their compounds. 

Whereas the first Ionization energies the energy to remove one electron) of the alkali metals are relatively low, the second Ionization energies are very high. 

Metal First Ionization energy/kJmoU Second Ionization energy/kJ mol  

They are all soft metals which tarnish in air, and for this reason they are generally stored under oil. The products obtained on burning the metals with oxygen, in the air, depend upon the metal  

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TABLE 14.3 Group 1 Elements The Alkali Metals Valence configuration ns1 Normal form soft, silver-gray metals ... 

As Table 21.1 indicates, the group 1 elements, the alkali metals, are relatively abundant. Some of their compounds have been known and used since prehistoric times. Yet these elements were not isolated in pure form until about 200 years ago. The compounds of the alkali metals are difficult to decompose by ordinary chemical means, so discovery of the elements had to await new scientific developments. Sodium (1807) and potassium (1807) were discovered through electrolysis. Lithium was discovered in 1817. Cesium (1860) and rubidium (1861) were identified as new elements through their emission spectra. Francium (1939) was isolated in the radioactive decay products of actinium. 

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