Germanium Tech Report
Overview
Germanium is a metalloid. A metalloid is an element that has characteristics of both metals and non-metals. Germanium is located in the middle of the carbon family, which is Group 14 (IVA) in the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. Carbon and silicon are above germanium and tin and lead are below it.
The existence of germanium was predicted by Russian chemist Dmitri Mendeleev (1834-1907), who developed the periodic table. Mendeleev predicted a new element would be found to fill an empty spot on the table. He was proved correct in 1886.
Until the 1950s, there were no important uses for germanium. Then, the transistor was invented. A transistor is a device used to control the flow of electricity in a circuit. Today, germanium is used in making a number of electronic devices, including the transistor.

SYMBOL
Ge

ATOMIC NUMBER
32

ATOMIC MASS
72.59

FAMILY
Group 14 (IVA)
Carbon
Physical properties
Germanium looks like a metal. It has a bright, shiny, silvery color. But it is brittle and breaks apart rather easily, which metals normally do not do. It has a melting point of 937.4°C (1,719°F) and a boiling point of 2,830°C (5,130°F). It conducts an electric current poorly. Substances of this kind are called semiconductors. Semiconductors conduct an electric current, but not nearly as well as metals like silver, copper, and aluminum.
The ability of semiconductors to conduct electricity depends greatly on the presence of small amounts of impurities. The addition of an impurity to a semiconductor is called doping. Doping a semiconductor has significant effects on its ability to conduct an electric current.
Chemical properties
Germanium is a relatively inactive element. It does not dissolve in water and does not react with oxygen at room temperature. It does dissolve in hot acids and with oxygen at high temperatures, however. It becomes more active when finely divided. It will combine with chlorine and bromine to form germanium chloride (GeCl4) and germanium bromide (GeBr4).