mercury Search Term: MercurySource Category: ASSISTMercury is the chemical element with the symbol Hg. It has the atomic number 80. It is a member of group 12 on the periodic table. Synonyms: mercury, elemental; quick silver; mercury metal; hydragyrum; CAS Number: 7439-97-6; Signal Word: Danger. Tags: Hghydrargyrumelement 807439-97-6quick silvermercury metal