* Resistivity: Resistivity is a measure of a material's opposition to the flow of electric current. In a solid, electrons can move freely through the material's structure, but in a gas, the molecules are far apart and don't form a continuous path for electrons to travel. Instead of resistivity, we talk about the breakdown strength of a gas, which is the electric field strength required to cause a spark or arc to form in the gas. SF6 has a very high breakdown strength, making it an excellent electrical insulator.
* Permeability: Permeability is a measure of a material's ability to allow magnetic fields to pass through it. Gases are generally considered to be diamagnetic, meaning they have a very weak magnetic permeability close to that of vacuum. This is because their molecules don't have a strong magnetic dipole moment. While SF6 has a very slight diamagnetic property, its significance is negligible compared to its electrical insulation properties.
In summary:
* Resistivity: Not directly applicable to gases. Instead, SF6 has a high breakdown strength.
* Permeability: Very low, essentially the same as vacuum.
If you're interested in the properties of SF6, you should focus on its electrical insulation capabilities, which are its most important characteristic in practical applications.
