What term refers to a metal technique in which a black sulfur alloy (mixture of metals) is rubbed into fine lines engraved into metal (usually gold or silver) and when heated, the alloy becomes fused with the surrounding metal and provides contrasting detail

When svante arrhenius first proposed his acid-base theory, he was a doctoral candidate. his professors thought his ideas were unfounded. within a decade, the arrhenius theory of acid-base was widely accepted and praised within the scientific world. arrhenius defined acids as compounds having ionizable hydrogen and bases as compounds with ionizable a) barium. b) hydronium. c) hydroxide. d) oxygen.