Bismuth is the chemical element with the symbol Bi and the atomic number of 83. It is a pentavalent post-transition metal and it is a pnictogen which resembles the lighter homologs arsenic and antimony.
Elemental bismuth can occur in nature, but it's oxide and sulfide forms are used industrially. It's pure form is 86% as dense as lead, and it is a brittle metal with a silvery-white color when freshly produced, but it oxidizes into a pink tinge. It is mildly radioactive and it is the most diamagnetic element, and it is the least thernally conductive metal on the periodic table.