[Chemistry Class Notes] Germanium Pdf for Exam

Germanium is a chemical element that is placed in the 14th group and 4th period in the periodic table. The symbol of the Germanium element is Ge. It is a metalloid with the atomic number 32. As Germanium is a metalloid, it shows some properties of metals and nonmetals as well. Metalloids are intermediate between metals and nonmetals. They are placed after metals and before the nonmetals in the periodic table. Thus, metalloids show the transition from metals to nonmetals. 

Metalloid Germanium belongs to the carbon family and shows similarity with neighbouring elements silicon and tin. Element Ge is present after Si and just above Sn in the 4th group of the periodic table. It is a lustrous and greyish-white element. 

Germanium was discovered late in the history of the discovery of chemical elements. Although Russian Chemist Dmitri Mendeleev predicted its existence in 1869 and named it Eka silicon, it was discovered in 1886 by German Chemist Clemens Alexander Winkler. He discovered it in argyrodite. Argyrodite is a rare silver Germanium sulfide mineral. Its formula is Ag8GeS6. Germanium resembles arsenic and antimony in appearance. 

The word Germanium comes from the country name Germany. Its discoverer Clemens Alexander Winkler named it after his country Germany. Clemens Winkler first named it Neptune but the name Neptune was already proposed for another element so he named it Germanium. It is not found in abundance in Earth’s crust like iron, aluminium, etc. It is mined from various ores such as sphalerite etc. Sphalerite is an ore of zinc although Germanium is found in ores of silver, copper, and lead as well. 

It has 5 natural isotopes which are 70Ge, 72Ge, 73Ge, 74Ge, and 76Ge. It has 27 synthetic isotopes as well which are unstable and have access to nuclear energy. 

Electronic Configuration of Ge (Germanium)

Germanium is a p- block element of the periodic table. Atomic number of Germanium is 32. Its electronic configuration is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p2 or it can be written as

Ar

Ar 3d10 4s2 4p2. It has 2 electrons in K – shell, 8 electrons in L – shell, 18 electrons in M – shell, and 4 electrons in its outermost shell N. 

Production of Germanium

Germanium is refined as a by-product and not as the primary material during the mining process of base metal. The main ores from which Germanium are extracted are sphalerite zinc ore, fly ash coal, and even some copper ores.

 Steps for extraction of Germanium:

• Irrespective of the main primary material the Germanium when undergoing chlorination and distillation process it produces Germanium tetrachloride (GeCl4).

• This Germanium tetrachloride is then further hydrolyzed and dried. The product of this reaction we get is Germanium dioxide (GeO2).

• Then we move ahead and reduce the oxide to form the Germanium powder (metal).

• After this, we perform the zone-refining process for which we first cast the bar with Germanium powder at a temperature greater than 1720.85 °F (938.25 °C).

• Once this is done we isolate the bars and start removing the impurities (zone-refining process begins).

• This process further at the end gives us a highly pure form of Germanium.

Occurrence of Germanium 

Germanium is not one of the abundant elements in the Earth’s crust. It is found in only a few ores such as argyrodite, briartite, germanite, and renierite. It has also been found in stars and in the atmosphere of Jupiter.

 

Properties of Germanium 

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The physical and chemical properties of Germanium are listed below –

• It is found as solid at STP. 

• The atomic mass of Germanium is 72.6.

• Its melting point is 938.25 ℃.

• The boiling point of Germanium is 2833 ℃.

• It shows a face-centered diamond cubic crystal structure.

• Its density is 5.323 g cm-3.

• It is a semiconductor. It means its electrical conductivity value is between that of the conductor and insulator. 

• According to the Pauling scale, its electronegativity is 2.01.

• Its 1st ionization energy is 762kJ/mol. 

• It has 5 natural isotopes which are 70Ge, 72Ge, 73Ge, 74Ge, and 76Ge. These all are stable isotopes. It has 27 synthetic isotopes which have high nuclear energy and are unstable. 

• It has a greyish–white appearance. 

• It has an allotrope – Germanium. 

• At 250 ℃, Germanium reacts with oxygen and forms oxide GeO2.

• It does not react with dilute acids and bases.

• It reacts with conc. hot H2SO4 and HNO3 slowly, but it reacts very violently with molten base. 

• Like water, Germanium expands when it freezes, unlike other elements.

• It reacts with chlorine and forms Germanium chloride. The reaction is given below – 

Ge + 2Cl2 ? GeCl4

Ge + 2Br2 ? GeBr4

Uses of Germanium 

Germanium is used in various fields mainly due to its properties such as semiconductor of electricity and high index of refraction of its oxide etc. A few of its uses are listed below –

• Germanium oxide is used in wide-angle camera lenses, microscopy, and optical fibres.

• It is used in rewritable DVDs.

• It is an important infrared optical material that is used in windows, thermal imaging cameras, etc.

• It is used in military appliances as well such as fire-fighting instruments, night vision instruments, etc. 

• It is used in alloys.

• It is used in fluorescent lamps. 

• Its optical fibres are used in communications and in infrared optics.

• It is used as a catalyst in many polymerization processes. 

• It is majorly used in solar cells and solar panels.

• It is used in metallurgy in the refining of metals.

• It has space applications. It is used in place of multijunction photovoltaic cells. 

• It is used in gallium arsenide solar cells.

• It is used in LEDs in its solid state.

• It can be used in gas chromatography columns in place of SiO2.

• It is used in the treatment of lung cancer and leukaemia. 

• It is also used in transistors as Germanium is a semiconductor in its elemental form.

Health Effects of Germanium 

The Germanium element is not an essential element for plants and animals. As it is present in very minute quantities in nature. So, it has very little impact on the environment as a biohazard. Some Germanium supplements are being used for the treatment of many diseases. 

Germanium plays a vital role in improving the O2 supply in the body, improving your immune system, and also destroying the free radicals that might affect your body and its proper functioning. However, there is no evidence available stating its benefits although some evidence suggests that these Ge supplements are harmful and can have side effects such as muscle weakness, anaemia, kidney damage, etc. 

The US FDA has concluded that inorganic Germanium presents potential human health hazards when taken as a nutritional supplement. According to research carried out at Memorial Sloan Cancer Centre, spiroGermanium – a derivative of Germanium has shown the ability to replicate fee cancer cells but as Germanium proves to be harmful to the human body the research was discarded.

Germanium Summary in Tabular Form 

 

Fun Fact

• A total of twenty-seven elements have been discovered by scientists.

• You won’t believe it but the half-life of a radioactive isotope of Germanium is 130 billion years.

• The atmosphere of Jupiter and some of the faraway stars have traces of Germanium.