What is Indium?
Indium is a chemical element with symbol In and atomic number 49. It is a post-transition metallic element that is rare in Earth's crust. It has no obvious role in biological processes, but is of considerable industrial importance. The metal is very soft, malleable and easily fusible, with a melting point higher than sodium, but lower than lithium or tin. Given its physical nature and position in the periodic table, it counts as a heavy metal, but in common circumstances is not a toxic hazard. Chemically, indium is similar to gallium and thallium, and it is largely intermediate between the two in terms of its properties.