Germanium is the third element of the fourteenth column of the periodic table. It is classified as a metalloid. It is similar in properties to the other metalloids near it in the periodic table which are silicon and arsenic. Germanium atoms have 32 electrons and 32 protons with 4 valence electrons in the outer shell.
Characteristics and Properties
Under standard conditions Germanium is a hard, shiny, silvery-gray solid that is very brittle. It is one of the few elements that expands when it freezes or turns solid.
As a metalloid, germanium has both metal and non-metal qualities. It also is a semiconductor, which means it has electrical conductivity between an insulator and a conductor. This characteristic has led to it being used in electronics.
Germanium does not react with oxygen at room temperatures, but will form germanium dioxide at higher temperatures.
Where is germanium found on Earth?
Germanium is a fairly rare element that is found in the Earth's crust. Although there are some minerals that contain a fair amount of germanium like germanite and argyrodite, they are too rare to be mined. The majority of germanium that is used by industry is produced as a byproduct of mining sphalerite zinc ore where it is found in small traces.
How is germanium used today?
The majority of germanium is used in optical systems. This is because Germania (GeO2) has good qualities for working with light and lasers. Applications like cameras, fiber optics, and microscopes take advantage of these qualities. It is also used in infrared optics.
Other applications include electronics (where it is combined with silicon to make silicon germanium (SiGe), solar cells, and some metal alloys.
How was it discovered?
Germanium was first predicted to exist by Russian chemist Dmitri Mendeleev in 1869 based on the periodic table. However, it was German chemist Clemens Winkler who first isolated the element and proved its existence in 1886. Winkler found the element in the mineral argyrodite.
Where did germanium get its name?
Germanium gets its name from Winkler's home country Germany.
Isotopes
There are five naturally occurring isotopes of Germanium. The most common is Germanium-74.
Interesting Facts about Germanium
Scientists are studying germanium for use in chemotherapy to help treat cancer.
Dmitri Mendeleev first named the element "ekasilicon", but it was later renamed by Winkler.
Some compounds that include germanium are useful in killing bacteria while not harming animals.
It is used as a catalyst to produce some types of plastics.
The majority of germanium that is mined is produced by China. A fair amount comes from recycling as well.
