Discovery of Argon                                                                                       

1785: It is prepared by Henry Cavendish, but it is not found to be a new element.

1882: H.F. Newell and W.N. Hartley, observing the color spectrum of air from two separate experiments, find a line in the spectrum that cannot be explained by the spectra of known elements, but do not realize that it is argon.

1894 - John William Strath and Scottish chemist William Ramsay determine argon as a new element. They compared the nitrogen produced by removing oxygen, carbon dioxide, and water vapor from an air sample with the nitrogen produced from ammonia, and found that the nitrogen produced from ammonia is 1.5 percent lighter than the nitrogen produced from air. Although the difference is small, it is large enough to be outside the margin of error. So they thought there should be a new gas in the air that nobody knew about, and that new gas was argon.

1894: The British Science Association met in Oxford and Rayleigh gave a report on the new gas, called argon (Greek for "not working" or "lazy"), based on President Madan's suggestion. Element symbol Ar. Of course, the argon found at that time was actually a mixture of argon and other inert gases, and it is precisely because the inert gas content of argon in the air is absolutely dominant, so it was found as a representative of the inert gas.

1957: The chemical symbol for argon is changed from "A" to "Ar", which has been used ever since.

                                                                                                              Sources of Argon                                                                                            

There are two main forms of argon in nature: one is argon in the air, the content in the air is 0.934% by volume, and 1.29% by mass, which is one of the most abundant rare gases on Earth; The other is argon gas in the earth's crust, which is mainly found in rocks and groundwater

Usually argon is obtained by air separation and distillation of liquefied air, and then further purified, high purity argon can be obtained. Liquid argon is the compression of high purity argon into a liquid gas and is stored in a Dewar tank. The national standard for high purity argon is GB/T10624-1995, and the purity is required to reach more than 99.999%.

                                                                                                               Uses of Argon                                                                                                  

Argon is mainly derived from its unique "inertia" of various uses, in addition to some other characteristics such as chromatography, low thermal conductivity, etc., also has some uses.

Metal working:

1.Aluminum: used to replace air or nitrogen, produce an inert atmosphere in the manufacturing process of aluminum; Helps remove unwanted soluble gases during degassing; And remove dissolved hydrogen and other particles from molten aluminum.

2.Steelmaking: used to replace gas or vapor and prevent oxidation in the process; Used to stir molten steel to maintain a constant temperature and the same composition; Helps remove unwanted soluble gases during degassing; As a carrier gas, argon can be used to determine the composition of the sample by chromatography. Argon can also be used in the argon-oxygen decarbonization process (AOD) used in stainless steel refining to remove carbon monoxide and reduce the loss of chromium.

3.Protective gas: argon is used as an inert protective gas in welding, which can avoid the burning of alloying elements and other welding defects resulting from it, so that the metallurgical reaction in the welding process becomes simple and easy to control to ensure the high quality of welding; Provides oxygen and nitrogen free protection during annealing and rolling of metals and alloys.

4.Smelting of special metals: lithium, beryllium, uranium, plutonium, titanium, zirconium, hafnium, tantalum and other nuclei and rare metals required for space industry reduction reaction, to use argon as an environmental gas.

Lighting:

1. Argon lamp: argon lamp is filled with pure argon. This kind of light is weak, consumes less power, and is cheaper than signal lights.

2. Neon: in the power state, argon can emit blue violet light. Create blue light in neon lamps. Therefore, argon and several other gases that give off color are filled with a light bulb, and this is how neon lights are made.

3. The lamp filling gas: used for white poncirus lamp and fluorescent lamp inflation. Because argon does not chemically interact with the filament even at high temperatures, it extends the life of the filament.

Medical and Pharmaceutical fields:

1. Operating room: can be used to keep the operating room clean and dry.

2. Medical argon knife: argon is also used in medicine, that is, argon knife. Argon knife is used to ionize argon under the action of high frequency current, and then the generated argon plasma has electrical conductivity, which can direct the current from the high frequency output electrode to the tissue. This method not only avoids direct contact between the electrode and the tissue, but also ensures that the current can enter every corner of the tissue flexibly. When the high-frequency current touches the tissue, it will deactivate and solidify the tissue through thermal effect. It is mainly used to treat tumors, but can also be used to connect arteries and treat defects in the eye.

3. Drug protection: Argon can be used to protect some intravenous therapy drugs, for example, such as acetaminophen, which is also to prevent the drug from being damaged by oxygen.

Scientific research:

1. Atomic physics and nuclear physics: Argon can be used to study the basic processes of atomic physics and nuclear physics, providing an important research tool.

2. Atmospheric physics: Argon plays an important role in atmospheric physics research and can be used to study various meteorological phenomena in the atmosphere.

3. Determine the age of groundwater, ice and igneous rocks: argon-39 has a half-life of 269 years, which can be used to determine the age of groundwater and ice, and potassium-argon dating method is suitable for the process of potassium-40 declination into argon-40 to determine the age of igneous rocks.

Other aspects:

1. Fire suppression: Argon can be used as a fire extinguisher for precision instruments. Keep them from being contaminated with oxygen and carbon dioxide. The advantage of using argon to extinguish a fire is that almost nothing will be destroyed in the fire, and it is usually used when there are special instruments in the fire.

2. The protective gas in the graphite electric furnace: so as not to oxidize it.

3. Cultural relics protection: In the museum, argon gas will be filled in the glass counters of some important cultural relics to avoid oxidation.

4. Silicon, germanium refining and single crystal preparation: semiconductor materials silicon, germanium refining and single crystal preparation to use argon as an environmental gas, to protect the growth of silicon crystals and germanium crystals.

5. Brewing: In the process of brewing, argon is filled into the beer barrel, which can replace oxygen to avoid the raw materials in the beer barrel being oxidized to acetic acid.

6. Sputtering: in a vacuum environment, through the appropriate argon gas (or other inert gas) as a medium, by argon to accelerate the impact of the target, so that the target surface atoms are hit out, and the formation of a coating on the surface.

7. Gas discharge tube: gas discharge tube refers to a type of lightning arrester or antenna switch tube for overvoltage protection, there are two or more electrodes in the tube, filled with a certain amount of argon (or other inert gases). As a gap type lightning protection element, it is used in lightning protection of communication systems.

8. Low heat transfer double glass: the double glass of the window can also be filled with argon. The Windows of high-rise buildings generally need to be installed with insulating glass, and argon gas is filled between the glass, which can isolate some outside heat, thus greatly reducing the thermal conductivity of the window glass. Living inside reduces heat loss. According to media reports, the glass of the high-speed rail is also double filled with argon.

9. Diving equipment: Argon can be used as a gas for expanding wetsuits in scuba diving. Argon can also be used in place of nitrogen in scuba (absorption of pure oxygen is not good for the body, so other gases must be added to scuba), because nitrogen will dissolve into the blood at high pressure and cause nitrogen anesthesia, argon can reduce this symptom.

10. Weapon cooling: The tracker used to cool the AIM-9 Sidewinder missile stores argon at high pressure, taking some of the heat away when the gas is released.

                                                                                                       Argon Hazard                                                                                                            

In general, argon is harmless to the body, but it has a choking effect in high concentrations. When the concentration of argon in the air is higher than 33%, there is a risk of suffocation, when the concentration of argon is more than 50%, there are serious symptoms, and when the concentration reaches more than 75%, death can occur within a few minutes. Liquid argon can cause explosions and frostbite.

                                                                                                        Peroration                                                                                                                 

Argon is an inert gas, with the increasing awareness of its application value, its role in life is more and more important. If you know or find what other applications of argon, welcome to leave a message to share with you!