Bismuth /ˈbɪzməθ/ is a chemical element that has the symbol Bi and atomic number 83. This heavy, brittle, white crystalline trivalent other metal has a pink tinge and chemically resembles arsenic and antimony. Of all the metals, it is the most naturally diamagnetic, and only mercury has a lower thermal conductivity. It is also generally considered as the last naturally occurring non-radioactive element.