All gases under normal conditions are good insulators, however, in a confined space gases, including the air, you can make guides. You need to artificially create them in moving the charge carriers, t. e. to ionize the gas molecules.

Show this by using the following experience. Take a large flat capacitor (rice. 20.1), it'll spread plate and connect them to a voltage source of several thousand volts. A sensitive galvanometer will show us, what is the current in the circuit no, although between the plates has an electric field. This means, what in the air between the plates free charges or no, or so little, the galvanometer does not respond to their movements. We shall see, that is correct the second statement.

Put between the plates of a burning candle or sent a beam of x-rays. In this case the galvanometer needle will deflect, t. e. in the chain will be current. So, in the air happened ionization molecules (appeared moving charge carriers). If you remove the ionizer, the current quickly disappears, as the air between the plates becomes again an insulator. On the basis of experiments of this kind was installed, what the ionization of the gas can be: high temperature, x-rays, ultraviolet rays, α-rays and t. d.

In Gaza, along with the ionization always occurs the reverse process — recombination of ions, t. e. the formation of the neutral molecules from ion gas. (Think, why in the continuous action of the ionizer and the absence of an electric field in Gaza is a sliding balance between the ionization of molecules and recombination of ions.)

In unit volume of the gas is the more movable charge carriers, the more intense ionizer, t. e. the more ions it creates per unit of time. During ionization of the gas molecules break away one of the valence electrons. Some of these electrons are attached to neutral gas molecules, forming negative ions, and some remains in the free state. Thus, mobile charge carriers in the ionized gas are free electrons and ions (as a positive, and negative). So conductivity ionized газа оказывается частично ионной и частично электронной.