Conduction of electricity in gases, Mechanical Engineering


Electricity can pass through different media. In the case of gases, the atoms or molecules are not packed and they are free to move. In fact, if we confine a gas in a container, the molecules of the gas move in a free random fashion. Because of the absence of charge carriers, unless we produce some charge carriers in the gas, it cannot conduct electricity. If the electrons (negatively charged particles) are made to come out of the binding of atoms, that is, if they are made free, than electricity. The process of freeing the electrons from the atoms is called "ionisation" of gas, because in this process not only electrons but also positively charged atoms are produced. The electron is bound to the atom. Therefore to  "free" the electron we have to supply energy to the electron. The energy which is supplied to the atom to remove the electron from the atom is called as the ionisation energy. The unit of energy for ionisation is called electron volts (eV) and it is equal to 1.62 x 10-19 Joules. Different molecules and atoms require different levels of ionisation energy or ionisation potentials.

Table  below gives the ionisation potentials of different gases.

When we ionise the gas, the gas becomes conductive because now the charge carriers are available. If we now apply a potential in the ionised medium, the charges will start to move and we will have current flowing through the ionised medium. The ions which have positive charge will move towards the cathode (-) and
the electrons will move towards the anode (+).



993_Ionisation potential.jpg

Posted Date: 9/13/2012 9:32:07 AM | Location : United States

Related Discussions:- Conduction of electricity in gases, Assignment Help, Ask Question on Conduction of electricity in gases, Get Answer, Expert's Help, Conduction of electricity in gases Discussions

Write discussion on Conduction of electricity in gases
Your posts are moderated
Related Questions
Manual Metal Arc Welding Manual metal arc (MMA) welding, is a type of manual arc welding process that uses a consumable electrode coated with flux to lay the weld. An electric

Choose either a plastic, composite, titanium alloy or aluminium alloy for the applications below and briefly explain your choice. In explaining your choice, relate the properties t

Cylinder Block: This serves as an enclosure to the cylinder. The cylinder is an integral part of cylinder block in 100 cc motorcycle. Figure : Cylinder Block

define elastomer.explain in details?

(a) Show that two statements of Second Law of thermodynamics are equivalent to each other. (b) A house that was heated by electric resistance heater consumed 1200 KWh of electri

All equipment that is critical to the plant's safety support; should always be located in a Safe Area (e.g. fire pumps, instrument/electrical equipment and an Emergency Assembly Ar

hardness of bore well water is less than sea water .justify

Gas Porosity Porosity is the presence of gas pockets or voids caused by the entrapment of gas evolved during weld metal solidification. This Porosity is caused due to im

Calculate the Spindle Speed by (a) HSS tool (b) Carbide Tool Calculate the spindle speed (N) if a C 20 steel job of 50 mm dia is to be turned by (a) HSS tool and (b) Carbide T