Welcome to the fifth instalment of the Element of the Month – a regular feature on the Radleys blog.
To choose the element of the month, we use a random number generator to produce a figure between 1 and 118 – the current number of elements in the periodic table. This month, we drew the number 32, making germanium our fifth element of the month.
What is Germanium?
Germanium has the chemical symbol Ge, the atomic number 32 and is a lustrous metalloid in the carbon group, chemically similar to tin and silicon.
It is the first element in the periodic table that is named after a country – Germany.
10 Interesting Facts About Germanium
1. Germanium was one of the elements that was unknown when Dmitri Mendeleev constructed the periodic table, but he predicted its existence based on the change in properties across the known elements in his table. His predictions were very close to what was later discovered.
2. In 1886, Clemens Winkler discovered a rare mineral called argyrodite which contained silver, sulphur and an unknown element, which Winkler named germanium after his home country.
3. In its pure form, the element is too reactive to occur naturally and is often found in compound state or in minerals.
4. Germanium is quite rare and found in the Earth at about 1.6 parts per million. The highest concentration has been found in coal seams.
5. Approximately 118 tons of germanium are produced annually and as it is recyclable, some of this is from reclaimed sources.
6. It is one of the few substances which expands as it solidifies, alongside silicon, gallium, bismuth, antimony and water.
7. Germanium has five naturally occurring isotopes: 70Ge, 72Ge, 73Ge, 74Ge, 76Ge. 76Ge is very slightly radioactive with a half-life of 1.78×1021 y – that’s 130 billion times the age of the universe.
8. Until the late 1930s, germanium was not understood and did not become significant until 1945 when it became widely used in electronics as a semiconductor in transistors. After a decade of semiconductor electronics being based on germanium, it was then replaced by ultra-high purity silicon.
9. In the present day, the main use of germanium is in fibre-optic systems, infrared optics and in solar cell devices. It has also been used in nanoelectronics in the production of nanowires.
10. Germanium has been found in the atmosphere of Jupiter and in distant stars.
There we have germanium, a fascinating precious metal which has been found across the universe.
Come back next month, when we’ll be investigating germanium’s close neighbour, tin.