The element in helium gas, the English name is Helium, the element symbol is He, and the atomic number is 2. Colorless and odorless inert gas, chemically inactive, usually difficult to react with other substances.

The nature of helium

Helium is a very light monoatomic gas, colorless, odorless, and odorless. Liquefied gas is a substance that cannot be solidified under standard atmospheric pressure. The results show that after the material is liquefied with liquefied gas, the surface tension is extremely low, the thermal conductivity is extremely high, and it has a certain degree of toughness. The use of helium at low temperatures is almost absolute zero.

Stable chemical properties are good, showing deep yellow under low pressure. Normally, the excitation of the low-voltage discharge tube will not produce compounds, but it will also form a molecule or a group of molecules. When the temperature drops to 2.18K, it is usually difficult to react with other substances. Under certain conditions, it can form complexes with certain metals, and the properties of helium will change, and the volume of helium will become very small. , It becomes a superfluid that flows upward along the wall of the container. Its thermal conductivity is 800 times that of copper. It becomes a conductor with high thermal conductivity. Its specific heat capacity, surface tension, and compressibility are abnormal. This abnormal liquid is called liquid helium II, while normal helium is called liquid helium I.

Uses of helium

1. Helium can be used as a booster and a booster for rocket liquid fuel, and is widely used in missiles, spacecraft and supersonic vehicles.

2. Helium is used as a shielding gas in the smelting and welding process, which is very important for the manufacture of helium, as well as aircraft, spacecraft, rockets and weapons.

3. Helium has good permeability and can be used to cool the cooling part of nuclear reactors, rockets and nuclear reactors, as well as electronic and electrical equipment.

4. Helium is an ideal gas, the most ideal gas in vapor pressure thermometers, and it is also suitable when the temperature is extremely low.

5. Helium has low density and is not flammable. It can be used to fill light bulbs, neon tubes, and it can also be used as an ideal gas for balloons and spacecraft.

6. Helium gas at close to absolute temperature (-273°C) can be obtained for the manufacture of superconducting materials.

7. A kind of inert gas, the solubility of helium in the blood is lower than that of nitrogen, so its anesthetic power is lower than that of nitrogen, so helium and oxygen are usually mixed as breathing gas for divers.