Symbol

In

Atomic Number

49

Atomic Mass

114.82

Family

Group 13 (Iiia) Aluminum Pronunciation

IN-dee-um

Overview

Indium is part of the aluminum family in Group 13 (IIIA) of the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. Indium was discovered in 1863 by German chemists Ferdinand Reich (1799-1882) and Hieronymus Theodor Richter (1824-98).

Indium has a number of interesting properties. For example, it has a low melting point for metals, 156.6^oC (313.9^o). When pure, it sticks very tightly to itself or to other metals. This property makes it useful as a solder. Solder is a material used to join two metals to each other. Other uses of indium are in the manufacture of batteries, electronic devices, and in research.

Discovery and Naming

Between 1860 and 1863, indium, cesium, rubidium, and thallium were found using spectroscopy. Spectroscopy is the process of analyzing light produced when...