Argon (Ar) is a colorless, odorless, and non-toxic inert gas with a relative atomic mass of 39.948. It is one of the components of air and is mainly produced through air liquefaction and distillation. Argon gas has stable chemical properties and is not easily reactive with other substances, so it has a wide range of applications in industry, such as being used as a welding shielding gas, bulb inflation, low-temperature freezing, photolithography process in semiconductor manufacturing, and inert atmosphere in scientific research experiments. In addition, argon gas has a density 1.4 times that of air at room temperature and is slightly soluble in water.

Oxygen (O₂) is an important component of the Earth's atmosphere, accounting for approximately 21% of the air volume and being the most abundant element. Oxygen is required for the oxidation of hydrocarbons, treatment of wastewater, rocket propellants, and for respiration of animals and humans in aviation, aerospace, and diving. Animal respiration, combustion, and all oxidation processes (including the decay of organic compounds) consume oxygen. But oxygen in the air can be continuously replenished through the photosynthesis of plants. In the cutting and welding of metals. It is a mixture of oxygen with a purity of 93.5%~99.2% and combustible gas (such as acetylene) to produce a flame at extremely high temperatures, thereby melting the metal. The metallurgical process cannot do without oxygen. Oxygen is also required to enhance the production process of nitric acid and sulfuric acid. By blowing a mixture of oxygen and water vapor into a gasifier without using air, high calorific value gas can be obtained. Medical gas is extremely important.

Carbon dioxide (CO₂) is a colorless and odorless gas that is an important component of the Earth's atmosphere and a key substance in many industrial processes and biological activities. In nature, carbon dioxide is absorbed by plants through photosynthesis and converted into oxygen, while also being released during respiration and combustion processes. As one of the greenhouse gases, carbon dioxide has a significant impact on the Earth's climate system, and excessive emissions can lead to global warming. In industry, carbon dioxide is commonly used in the production of carbonated beverages, frozen foods, and as a protective gas in welding and firefighting.

Nitrogen (N₂) is one of the main components of air, accounting for approximately 78% of the total Earth's atmosphere. It is a colorless, odorless, and tasteless inert gas with stable chemical properties that is not easily reactive with other substances. In industrial production, nitrogen is often used as a protective gas, such as in welding, cutting, and food packaging processes, to prevent oxidation and corrosion caused by oxygen. In addition, nitrogen is also used in the manufacture of fertilizers, synthetic fibers, and as a refrigerant for freezing and refrigeration. Due to its inertness, nitrogen is also commonly used as an inert atmosphere in laboratories to protect sensitive substances from the influence of air.

Liquid nitrogen (LN₂) is the liquid form of nitrogen gas converted at extremely low temperatures (typically -196 ° C). It exhibits colorless, odorless, and tasteless characteristics, and is often used in various low-temperature applications due to its extremely low temperature. In scientific research, liquid nitrogen is often used as a cryogen for preserving biological samples, cryotherapy, and superconducting experiments. In addition, liquid nitrogen is also used in the food industry for rapid freezing of food to maintain its freshness and taste. At the same time, liquid nitrogen is also used to manufacture specialty foods such as liquid nitrogen ice cream, bringing people a unique taste experience.

Gas Mixture refers to a gas composed of two or more gases mixed in a certain proportion. It is widely used in industrial, medical, scientific research and other fields to meet different needs. For example, a mixture of argon and carbon dioxide is commonly used as a shielding gas in welding; In healthcare, a mixture of oxygen and nitrogen can be used for respiratory therapy.

Sulfur dioxide (SO₂) is the most common and simplest sulfur oxide, which is a colorless and transparent gas with a pungent odor. Dissolve in water, ethanol, and ether. Sulfur dioxide is one of the main pollutants in the atmosphere. During volcanic eruptions, this gas is released, and in many industrial processes, sulfur dioxide is also produced. Due to the presence of sulfur in coal and petroleum, sulfur dioxide is generated during combustion. When sulfur dioxide dissolves in water, it forms sulfurous acid. If sulfurous acid is further oxidized in the presence of PM2.5, it will rapidly and efficiently generate sulfuric acid (one of the main components of acid rain). This is one of the reasons for concerns about the environmental effects of using these fuels as energy sources.

Propane (CH₃CH₂CH₃) is an organic compound that is a colorless and odorless gas. It is slightly soluble in water and soluble in ethanol and ether. Its chemical properties are stable and not prone to chemical reactions, and it is commonly used as a refrigerant, internal combustion engine fuel, or organic synthesis raw material. Propane is flammable and explosive, and when mixed with air, it can form explosive mixtures. There is a risk of combustion and explosion when exposed to heat sources and open flames. In industry, propane is also used as an important raw material for cracking to produce ethylene and propylene, as well as for the production of other nitro compounds and solvents.

Isobutane (C₄H₁₀), also known as 2-methylpropane, is an organic compound that is a colorless flammable gas at room temperature and pressure. Slightly soluble in water, soluble in ethanol, ether, etc., it forms explosive mixtures with air and mainly exists in natural gas, refinery gas, and cracking gas. It is obtained through physical separation and is mainly used for the alkylation of isobutene to produce isooctane. It is used as a gasoline octane number improver and can also be used as a refrigerant.

Liquid argon (LAr) is a liquid argon gas with the chemical formula Ar. It is a colorless, odorless, and non-toxic inert gas that is slightly soluble in water. Its melting point is -189.2 ℃ and boiling point is -185.9 ℃. Liquid argon is mainly prepared by air separation method and has a high content in air. It is a rare gas. It has wide applications in various fields such as industry, healthcare, and food processing, such as as as a coolant, gas protectant, rocket propellant, etc. It is also commonly used in industries such as photovoltaics, semiconductor manufacturing, metal cutting and welding.

Liquid oxygen (LO₂) is the liquid form of oxygen, appearing light blue and transparent. At standard atmospheric pressure, its boiling point is -182.96 degrees Celsius. As an efficient oxidant, liquid oxygen plays an important role in various fields such as medical, industrial, and aerospace. In the medical field, it is used for oxygen supply in hospitals and emergency stations to help patients maintain their lives. In industry, liquid oxygen is commonly used in steel smelting, non-ferrous metal smelting, and chemical product production to improve production efficiency and product quality. In addition, liquid oxygen is also used as a combustion aid for rocket engines, providing power for spacecraft launch and operation. Due to its low-temperature characteristics and high purity requirements, the production, storage, and transportation of liquid oxygen must strictly comply with safety regulations.