Nature:
Element Name: Germanium
Element symbol: Ge
English name of element: germanium
Element type: metal element
Atomic volume: (cc/mol) 13.6
Content of elements in the universe: (ppm) 0.2
Element content in the sun: (ppm) 0.2
Element content in seawater: (ppm) 0.0000035 Pacific surface.
Content in the shell: (ppm) 1.8
Germanium particles.
Relative atomic mass: 72.6 1
Oxidation state: main Ge+2, Ge+4.
Chemical bond energy: (kJ/mol)
Ge-H 288
Germanium carbon 237
Ge-O 363
Ge-F 464
Germanium chloride 340
Ge-Ge 163
Atomic number: 32
Number of protons: 32
Neutron number: 4 1
Molar mass: 73
Period: 4
Number of families: IVA
Electron layer arrangement: 2-8- 18-4
Crystal structure: the unit cell is a face-centered cubic unit cell, and each unit cell contains 4 metal atoms.
Cell parameters:
a = 565.75 pm
b = 565.75 pm
c = 565.75 pm
α = 90
β = 90
γ = 90
Mohs hardness: 6
The speed of sound propagation in it: (m/S)5400.
Ionization energy (kJ/mol)
M - M+ 762. 1
M+ - M2+ 1537
M2+ - M3+ 3302
M3+ - M4+ 44 10
Germanium ore
M4+ - M5+ 9020
M5+ - M6+ 1 1900
M6+ - M7+ 15000
M7+ - M8+ 18200
M8+ - M9+ 2 1800
M9+ - M 10+ 27000
Color and state: silvery white solid
Density: 5.35g/cm3
Melting point: 937.4℃
Boiling point: 2830℃
Atomic radius: 122 picometers, Ge4+ radius 53 picometers.
Discoverer: Winkler's year of discovery: 1886.
Discovery process: 1886, Germany Winkler discovered the existence of germanium when analyzing the silver-germanium sulfide ore; After that, germanium sulfide is heated with hydrogen to produce germanium.
physical features
Germanium is a silver-gray crystal with a melting point of 937.4℃, a boiling point of 2830℃ and a density of 5.35g/cm3 (2.
Germanium ingot
0℃), the Mohs hardness is 6.0 ~ 6.5. At room temperature, crystalline germanium is brittle and has little plasticity. Germanium has semiconductor properties. P-type germanium semiconductor is obtained by doping trivalent elements (such as indium, gallium and boron) into high-purity germanium. Doping pentavalent elements (such as antimony, arsenic and phosphorus) to obtain N-type germanium semiconductor. Germanium does not oxidize in air at room temperature, but can burn in oxygen, chlorine and bromine vapor when heated. Germanium does not react with water and is insoluble in hydrochloric acid and dilute sulfuric acid. Nitric acid and hot concentrated sulfuric acid can oxidize germanium into germanium dioxide, and germanium is also soluble in aqua regia. Germanium is easily soluble in molten sodium hydroxide or potassium hydroxide to form sodium germanate or potassium germanate. In the presence of oxidants such as hydrogen peroxide and sodium hypochlorite, germanium can be dissolved in alkaline solution to form germanate. The oxidation states of germanium are +2 and +4.
use
High purity germanium is a semiconductor material. It can be extracted from high-purity germanium oxide by reduction smelting. Germanium single crystal doped with trace specific impurities can be used to make various transistors, rectifiers and other devices. Germanium compounds are used to make fluorescent plates and various glasses with high refractive index. Germanium single crystal can be used as transistor and is the first generation transistor material. Germanium is used in radiation detectors and thermoelectric materials. High-purity germanium single crystal has high refractive index, is transparent to infrared rays, and is opaque to visible light and ultraviolet rays, and can be used as a germanium window, prism or lens specially transmitting infrared rays. The compound of germanium and niobium is a superconducting material. Germanium dioxide is a catalyst for polymerization. The glass containing germanium dioxide has high refractive index and dispersion performance, and can be used as a wide-angle camera and microscope lens. Germanium tetrachloride is also a new fiber material additive.
Germanium, with semiconductor characteristics. It has played an important role in the development of solid state physics and solid state electronics. Germanium has a melting density of 5.32g/cm3, which is a silver-gray brittle metal. Germanium can be classified as a rare metal. Germanium is chemically stable and does not react with air or water vapor at room temperature, but at 600 ~ 700℃, germanium dioxide is rapidly generated. It has no effect on hydrochloric acid and dilute sulfuric acid. When concentrated sulfuric acid is heated, germanium will slowly dissolve. Germanium is easily soluble in nitric acid and aqua regia. The interaction between lye and germanium is weak, but molten alkali in the air can dissolve germanium quickly. Germanium does not react with carbon, so it melts in graphite crucible and will not be polluted by carbon. Germanium has good semiconductor properties such as electron mobility and hole mobility. There is great potential for the development of germanium. Germanium produced in modern industry mainly comes from the by-products of copper, lead and zinc smelting.
In the process of pyrometallurgical zinc smelting, germanium enters the dust in the form of chloride or oxide and is enriched. Germanium produced by coal combustion or coking industry is enriched in flue dust. Germanium tetrachloride can be obtained by treating smoke with hydrochloric acid. After rectification and purification, high-purity germanium dioxide was obtained by hydrolysis, which was placed in a quartz tube, heated to 680℃ and reduced with hydrogen to obtain high-purity germanium. Then germanium single crystal is obtained by Czochralski method or zone melting method. Although germanium has been largely replaced by silicon in the electronic industry, it still has advantages in infrared devices and gamma radiation detectors because of its higher electron and hole mobility and better performance in high-speed switching circuits. Germanium can also be used as a catalyst for coal hydrogenation and petroleum refining, and bismuth germanate can be used as a scintillator radiation detector.
Influence on people
The main function of germanium on human body is to restore fatigue; Prevention of anemia; Help metabolism and so on. Many places are used as medical AIDS. But it has not been clinically proved to be effective. At most, they will say: the body will be lighter and the pain will be relieved. If you take it, there have been deaths. What clinical researchers think is dangerous. It will have a bad effect on the kidneys. But in Japan, it is sold in necklaces and bracelets as a health care appliance in the jewelry industry. It is very expensive
So far, germanium has not been found to be an essential trace element for human body, and no organism has been found.
Germanium particles
Due to the pathological changes caused by germanium deficiency, it is generally not necessary to supplement germanium, because germanium can already be ingested by the human body in a sufficient amount in the normal diet. At present, it is found that the beneficial biological effects of germanium are closely related to the existing forms, and it seems that there is no obvious physiological activity. Only some organic germanium compounds can show certain physiological activities.
Distribution and metabolism of germanium in the body
All kinds of natural foods contain germanium to varying degrees, and the daily intake of germanium for adults is about 400-3500ug. Therefore, germanium is ubiquitous in the body, and some enzyme proteins in the body, the cortex and gray matter of the brain all contain trace element germanium.
Second, organic germanium compounds with physiological activity
The most studied organogermanium compounds include organogermanium sesquioxides, derivatives and sulfur-containing coordination organogermanium compounds, and their physiological activities are the most obvious.
Germanium has obvious anti-tumor and anti-inflammatory activities, and there are many other types of organic germanium compounds, most of which have anti-tumor, anti-inflammatory, immune resurrection, sterilization and other biological effects, but because of their high toxicity, they can only be used as medicine.
Third, the relationship between organic germanium compounds and tumors
Organic germanium 132 and spirogermanium have obvious anti-tumor activity and low toxicity, especially
Germanium powder
Without the advantage of bone marrow toxicity, it has great potential in preventing and treating tumors and assisting radiotherapy and chemotherapy, and has entered the clinical trial stage.
The possible mechanisms of organogermanium compounds inhibiting tumor activity include enhancing immunity, scavenging free radicals and resisting mutation. In many bioactive organic germanium compounds, strongly electronegative atoms such as oxygen, sulfur and nitrogen are usually coordinated with germanium atoms. Because they absorb electrons, the electron clouds around germanium atoms deviate from the nucleus and form a positive center. When organic germanium compounds meet tumor cells, its normal center can increase the potential energy of tumor cells and reduce their activity, thus playing a role in inhibiting and killing tumor cells, that is to say, organic germanium compounds inhibit tumor activity. In addition to anti-tumor and immune resuscitation, germanium is also beneficial to biological effects, including stimulating hematopoietic system function, inhibiting cell growth, promoting antibacterial disappearance, and promoting plant growth. The effect on the blood system is mainly manifested in stimulating the increase of the number of red blood cells and hemoglobin in the blood, which has a certain effect on the treatment of anemia. Agree 44| Comment (3)