铋（Bismuth）是一种化学元素，它的化学符号是Bi，它的原子序数是83，是有银白色光泽的金属。

铋的化学性质与砷及锑类似。铋是最反磁性（又称抗磁性）的金属，亦是除汞以外有最低热导率的金属。铋还拥有最高的霍尔系数 ，它具有较高的电阻 。当铋以级薄的层在物体表面沉积是有半导体的性质，尽管铋是一个后过渡金属。可用于制备易熔合金及与锡融合防止锡疫。

铋是一种脆性金属，在自然界中，常以单质形式出现。铋晶体的表面有时会呈现出不同颜色的色调，这是由于铋晶体在空气中氧化时形成的氧化层厚度不一，导致不同波长的光受到不同程度的反射，因此呈现出彩虹的颜色。

Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a pentavalent post-transition metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery white color when freshly produced, but is often seen in air with a pink tinge owing to surface oxidation. Bismuth is the most naturally diamagnetic element, and has one of the lowest values of thermal conductivity among metals.