Addition of this element to the ethyl ester of pimelic acid creates an intramolecular ring in one method for the synthesis of tropolone. An amalgam of this metal reduces a quaternary ammonium cation to a tertiary amine in the Emde (EM-duh) degradation. That amalgam of this metal is dissolved in methanol to catalyze the last step of the Julia olefination. Two alkyl (15[1])halides couple to an alkane when treated with this metal (-5[1])in a reaction named for Charles (*) Wurtz. An irritant commonly used as a foaming agent in toothpaste and soap is this metal's lauryl sulfate. (10[2])This metal (10[1])is a source of solvated electrons (10[1])that convert an arene to a radical anion in the first step of the Birch reduction. In oxymercuration, alkenes are reduced to alcohols by this metal's borohydride. For 10 points, name this metal whose hydroxide neutralizes hydrochloric acid to form table salt. ■END■ (10[1])