Bismuth is a crystalline, brittle, metal. Lying on the right side of the periodic table, bismuth is the most naturally diamagnetic metal (it is the most resistant to being magnetized). It also has a high electrical resistance. Its thermal conductivity is lower than any metal, except mercury. Bismuth also has the unusual property that (like water) it expands as it freezes. Four other elements expand when they freeze; silicon, gallium, antimony and germanium.