Stable isotope of argon argon -40 (40Ar) natural content of 99.6%, argon -36 (36Ar) natural content of 0.34% and argon -38 (38Ar) natural content of 0.06%. Generally stable argon -40 is captured by the earth's crust or potassium -40 (40K) via electron positron emission decay come. Potassium-40 to argon decays into two methods account for only 11.2% plus 88.8% argon from the decay of calcium through -40 (40Ca) of β. This feature can be used to determine the age of the rock. [12]
In the Earth's atmosphere, unstable argon -39 (39Ar) may argon bombardment -40 generated by cosmic rays, the other can also capture comes via K -39 (39K) neutrons. As for the artificial isotope of argon -37 can be formed from (37Ar) nuclear tests of calcium decay of argon-37 life expectancy is very short half-life of only 35 days.
Compound
Since argon has eight valence electrons, which occupy the outermost atomic orbits, it is not easy to combine with other atoms, chemically very inert. In 1962, it is generally believed that argon and other inert gases are completely unable to produce other chemical reactions, but soon after the ratio of the compound of argon heavy xenon and krypton succession are synthesized, and therefore encourage scientists to discover new rare gas compound. In August 2000, the first compound of argon at the University of Helsinki in Finland by Maku Lhasa, will lead the team out of the first to be prepared, they contain trace amounts of hydrogen fluoride by ultraviolet irradiation of argon ice, forming a hydrogen argon fluoride , the formula HArF, this compound can be kept stable at 40K (-233 ° C) Temperature. [13] also found that a new compound in the presence of traces of argon in 2003, two argon fluoride (ArF2), but there is no reliable evidence to support.
description:
Which is a single-atom molecule, simple substance is a colorless, odorless and tasteless gas. The rare gas is one of the largest content in the air, the air contains about 100 liters 934 ml. Density of 1.784 g / liter. Melting point -189.2 ℃. The boiling point of -185.7 degrees. Ionization energy 15.759 eV. Chemically extremely inert, compounds according to the general sense of the word, it will not form any compound. Argon does not burn, nor combustion.
source:
Currently argon obtained in an industrial process is to air distillation. 90.2K condenser can put boiling point of liquefied oxygen, after the removal of oxygen can be further cooled liquefied argon 87.3K boiling point, boiling point and finally left 77.35K nitrogen. Currently produced in this way in the world of argon up to 70 million tons / year.
Other methods
Further use of potassium-40 decays can also manufacture argon, but the efficiency of this method of preparation is not high, because the half-life of potassium-40 up 1.26 × 109 years, so it was not commonly used. If you want to manufacture radioactive isotopes of argon, then it must rely on the cyclotron and the heavy ion accelerator to convert other elements into argon isotopes.
Natural content
Argon content in the earth's atmosphere by volume calculated as 0.934 percent, while the quality is calculated as 1.29%, as in the earth's crust can be said to be completely free of argon because argon does not react with other compounds in natural circumstances, and can not form a solid substance. Because of this mostly for industrial use argon are extracted directly from the air. Mainly extracted by fractional distillation, and like nitrogen, oxygen, neon, krypton, xenon and other gases are also extracted from this air. [10] and in the atmosphere of Mars, argon -40 in terms of volume, then holds 1.6%, while the concentration of argon is -36 5ppm; additional 1973 Mariner program space probe flew Mercury and found it thin atmosphere It occupies 70% argon, argon scientists believe that these are the rock itself from Mercury radioisotopes from the decay. Cassini - Huygens at Saturn's largest moon, Titan is also found a small amount of argon.
Argon purification
Industrial helium congeners main impurities are nitrogen, oxygen, carbon dioxide · Water · · · monoxide and hydrocarbons
1 nitrogen and nitrogen, sometimes accompanied by oxygen, metal getter absorbing and metal getter calcium, titanium, uranium and zirconium aluminum 16.
Do calcium metal getter, while the absorption of nitrogen and oxygen, the reaction temperature is 650-680 ℃, export impurity 20-50 PPm
Titanium, zirconium, aluminum 16 can absorb oxygen, nitrogen, hydrogen, steam, carbon monoxide, carbon dioxide and hydrocarbons
Deoxy-2-deoxy-chemical method, commonly used deoxidizer manganese oxide and Ag-X zeolite
Manganese oxide absorbs oxygen, temperature 150 ℃, oxygen removal to 2PPm
Ag-X zeolite at room temperature with oxygen, oxygen removal to 3PPm
3 dehydrogenation removal of hydrogen peroxide and copper Pd-X zeolite
· Removal of hydrogen with copper oxide, the reaction temperature is 350-400 ℃, hydrogen off to 0.1PPm
With Pd-X zeolite · removing hydrogen, the reaction temperature is 350-400 ℃, hydrogen off to 1PPm
4 carbide removal,
Aluminum zirconium metal 16 decarbonization agent, while a one-time removal of carbon monoxide, carbon dioxide, and hydrocarbons up to 1PPm
Elements Uses:
The earliest use of argon is blown up inside the bulb. Welding and cutting metals may also use a lot of argon. Used for arc welding of stainless steel, magnesium, aluminum and other alloys protective gas, namely welding
Argon
Argon is a colorless, odorless inert gas, the molecular weight of 39.938, the formula Ar, under standard conditions, having a density of 1.784kg / m3. Its boiling point -185.7 ℃
use
Containing argon and mercury vapor can be neon.
The yard is equipped tub argon, can be used for fire fighting.
Because the nature of the inert argon gas, low heat transfer rate, so it is widely used in many ways.
The main usefulness of argon is its inertness, can protect something likely to occur with the surrounding physical reactions. Although other inert gases have these features, but a maximum of argon in air content, the most readily available, so it is relatively inexpensive, has economic benefits. Also argon cheap reason it is also a byproduct of the manufacture of liquid oxygen and liquid nitrogen, and as an important raw material on both of them are industrial, production lot, so every year there are a lot of liquid argon by-product.
Inert argon purposes are:
1. in the gas-filled bulb, since argon does not produce a chemical reaction with the wick, so it will not burn the wick.
2. argon can be used as a protective gas used in welding, including MIG welding, GTA welding and GMA welding, at which point an argon and carbon dioxide are usually mixed together. [15]
3. Can be used for fire extinguishing, fire extinguishing with argon benefit is hardly any fire damage items, usually in the fire so that when there is a special instrument.
4. The gas used is one of the inductively coupled plasma. [16]
5. protection for metal machining titanium and other readily react.
6. Protect growing crystals of silicon and germanium crystals, which is mainly used in the semiconductor crystal learn.
7. In the museum, will be filled with argon gas in a number of important cultural relics in glass counter, to avoid oxidation. [17]
8. In the beer filler, although it could be replaced with nitrogen.
9. In the brewing process, the kegs in the filler, it can be replaced with oxygen, to avoid the kegs in the raw material is oxidized to acetic acid.
