for metallic conductors and electrolytes current dependence on voltage is linear, ie. E. The current in these conductors increases in proportion to the voltage.Much more complicated laws of conduction in gases.Consider an electric current in the gases flowing under the influence of an external ionizer.
Referring to the experience.Take a capacitor and charge it, creating a tension between its plates.An electrometer connected to the capacitor plates, all the time shows the same voltage: hence, the air in the normal conditions of an insulator, t. E. Does not contain free charged particles.
Vnesёm or alcohol lamp lighted match into the area between the two plates of the capacitor.We note that the tension between them decreases, the capacitor is discharged, therefore, between the plates of an electric current.All this indicates that the air between the plates under the action of the flame were charged particles.What do they represent?
It is natural to assume that these charged particles are air molecules, which under the influence of flame got electrical charges and turned into ions, began to move in the electric field between the plates, creating an electric current in gases, which led to a decrease in the voltage across the capacitor plates.
Through careful research, it was found that the electric charge carriers in the gas are ions and electrons, which occur in the gas as a result of exposure to ionizing.
ionizers are flames, X-rays, the rays emitted by radioactive substances.Any ionizer, of whatever origin it may be, has the ability to create in the amount of some time a certain amount of positive and negative ions.
Under the influence of ionizing the gas molecules lose their electrons and become positively charged ions.The released electrons, firstly, themselves become carriers of electric charges, and secondly, joining the neutral molecules or atoms to form ions, which are negatively charged.Since the gas can occur in the form of the free charges of the electrons and ions of both signs, t. E., An electric current in the gases.
charged body, being in the ionized gas, attracts free charges of opposite sign, which neutralizes the charge on the body, so that it is discharged.
The gas does not occur discharge their contents on the electrodes, as occurs in electrolytes, since the ionization of the gas molecules do not break it;they just lose or attached to the electrons themselves.
gas ions approaching the electrode to give him their charges, turning into neutral molecules or atoms, and diffuse back into the gas.The same electrolyte ions coming up to the electrodes, or deposited on the electrode surface or react chemically.
If the ions and free electrons generated in the gas are in the electric field, they become directional movement.From this it follows that the total electrical current in the gases - is two streams of charged particles, one of which goes to the anode, and the second - the cathode.He is accompanied by a number of peculiar phenomena.These include various types of emission of the gas in the discharge - from a weak, barely discernible glow of high voltage to the dazzling glare of the electric arc and the grand flashes of lightning.Electric current in the medium (solid conductors, electrolytes) does not cause such phenomena.
Finally, when the gas discharge can be observed and the specific chemical reactions not occurring during normal conditions of: the formation of oxides of nitrogen and cyanogen in air, the formation of a monoatomic molecules and other gases.
