Hey what is the most conductive gas that can be easily found. and will lowering the pressure increase the conductivity?
In answer to part 1 of your question:
- Argon is readily available (check welding supply centers) and has about 1/5 the dielectric strength of air.
- Helium, also fairly available, has about 1/6.5 the dielectric strength of air.
In answer to part 2 of your question:
Yes, reduced pressures generally reduce the dielectric strength of gasses.
(note: Lower dielectric strength = less barrier to conductivity & once a gas's dielectric is "broken," the resulting arc creates a highly conductive plasma)
Gases have extremely low electrical conductivity, all of them. This is because they are basically a vacuum with "a few" electrically neutral molecules in it.
When you ionize such molecules by some mean (e.g. increasing the temperature) you obtain what is called a plasma, which you can imagine as gas made by ions and electrons.
In particular, if you have a gas container with electrodes in it, and you apply a voltage above a ceratin value, called breakdown voltage of the gas, you can ionize the gas (this technique has many applications in electrical engineering and applied physics).