Plasma vs Gas
Matter exists in different status. We mainly recognize three states as solid, liquid and gases. Other than these main forms, there can be bit different states where matter doesn’t show all the characteristics of the main states. Plasma is one such state.
Gas is one of the states which matter exists. It has contradictory properties from solids and liquids. Gases do not have an order, and they occupy any given space. Individual gas particles are separated and have a great distance between them in a mixture of gas compared to a solution or a solid. Therefore, they don’t have strong intermolecular forces. Their behavior is greatly affected by variables such as temperature, pressure, etc. When a high pressure is applied, gases reduce the volume and when the pressure is released they expand and fill up the total space given. Atmosphere consists of various types and amount of gases. Some gases are diatomic (nitrogen, oxygen), and some are monoatomic (argon, helium). There are gases consisting of a single element (oxygen gas), and some have two more elements combined (carbon dioxide, nitrogen oxide). Gases can be colorless or colorless. Normally a colored gas would appear colorless to our naked eye if they are distributed over a large volume. Some gases have a characteristic smell (hydrogen sulfide). Most of the time it is very difficult to recognize a gas if they don’t have a characteristic physical property. Scientists like Robert Boyle, Jacques Charles, John Dalton, Joseph Gay-Lussac and Amedeo Avogadro have studied about various physical properties of gases and their behaviors. We know of ideal gas and real gas laws that they have presented. Ideal gas is a theoretical concept which we use for our study purposes. For a gas to be ideal, they should have following characteristics. If one of these is missing, then the gas isn’t considered as an ideal gas.
• Inter molecular forces between gas molecules are negligible.
• The gas molecules are considered as point particles. Therefore, compared to the space where the gas molecules occupy, molecules’ volumes are insignificant.
An ideal gas is characterized by three variables, pressure, volume and temperature. Following equation defines ideal gases.
For a gas, when one or both the above two given assumptions are invalid, then that gas is known as real gas. We actually encounter real gases in the natural environment. A real gas varies from the ideal condition at very high pressures and low temperatures.
This is a state of matter similar to gas, but has few differences. Similar to gas, plasma doesn’t have an exact shape or volume. It fills up the given space. The difference is that, though it is in the gas state, part of the particles is ionized in plasma. Therefore, plasma contains charged particles like positive and negative ions. This ionization can be carried out by various methods. One method is heating. Further, plasma can be generated by applying electromagnetic radiation like microwave or laser. These radiations cause bond dissociation, thus generate charged particles. Since there is a considerable amount of charged particles, plasma can conduct electricity. Because of the special characteristics stated above, plasma is considered to be a distinct state of matter separated from solid, liquid or gas.
What is the difference between Gas and Plasma?
• Plasma contains permanently charged particles compared to gases.
• Plasma can conduct electricity better than gases.
• Since plasma contains charged particles, they respond to electric and magnetic field better than gases.