Its aluminum hydride works excellently in the reduction of ketones and aldehydes to alcohols, and along with magnesium it is the most common metal used in organometallic reagents.  
Cockroft and Walton used it as the target metal in transmitting nuclei by artificially accelerated molecules.  When combined with paraffin and oil under high pressure, it first yielded artificial diamonds.  Its aluminum hydride works excellently in the reduction of ketones and aldehydes to alcohols, and along with magnesium it is the most common metal used in organometallic reagents.  Also of note is that its lightest isotope, when bomarded with slow neutrons, yields a tritium and helium.  FTP, name this first of the alkali metals, whose carbonate is often used in treating manic depression.
Cockroft and Walton used it as the target metal in transmitting nuclei by artificially accelerated molecules.  
lithium