The s-Block Metals as Reducing Agents

The s-block metals are among the strongest reductants known and reduce most materials capable of reduction. The reaction with water is shown below for a generic alkali metal (M)  

Note carefully the nature of the two arrows, a fishhook to indicate movement of a single electron and a normal double-headed arrow to indicate the movement of an electron pair. 

The hydrogen atom produced in the above reaction then combines with another one to form 

An analogous reaetion also happens with alcohols (ROH). 

The metals reduce halogens and other nonmetals to yield binary salts, as illustrated below 

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