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. (-5[1])Two alkyl (15[1])halides couple to an alkane when treated with this metal (-5[1])in a reaction named for Charles (*) Wurtz. (10[1]-5[1])An irritant commonly used as a foaming agent in toothpaste and soap (10[1])is this metal's lauryl sulfate. (10[6])This metal (10[1])is a source (10[1])of solvated electrons (10[1])that convert an (10[1])arene to a radical anion in the first step of the Birch reduction. (-5[1])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. (10[1])■END■ (10[5])