what gases are good insulators
Gases with electronegative species (i.e. halogens such as chlorine) make good insulators, hence the popularity of SF6, which is not only dense (breakdown voltage is roughly proportional to density) but is mostly Fluorine, a highly electronegative element.ulfur Hexafluoride (SF6) - Sulfur Hexafluoride is probably the most popular insulating gas, although its cost has risen dramatically recently. Hydrogen-Hydrogen gas is not a particularly good insulator (65% of air) from a breakdown voltage standpoint.