Gas: The Kinetic Molecular Theory

Gas is one of three states. The state of the gas consists of a set of freely moving molecules that are independent of each other. Some properties define the gas and can separate the state of matter from the other two states: solid and liquid. A wide variety of energies, forces and quantities can greatly influence the behavior of all kinds of gases. These differences include pressure, temperature, volume, and even the number of molecules in the gas element. There is a mathematical relationship between all these attributes, and all attributes are only affected if one attribute is changed.

The ideal gas process deals with macroscopic quantities of gas, but molecular dynamics theory shows how individual gas particles interact. Dynamic molecular theory contains many descriptions consistent with ideal gas law assumptions. It is worth listing them here: The amazing thing about dynamic molecular theory is that it can be used to derive the ideal gas law. This derivation links the microscopic assertion of dynamic molecular theory with the very obvious macroscopic behavior of the ideal gas law. Derivation is beyond the scope of this explanation, but if you are interested you should tell your teacher

Kinetics explains the macroscopic nature of gases such as pressure, temperature, viscosity, thermal conductivity, volume by considering their molecular composition and motion. In theory, gas pressure is caused by particles colliding with the container wall at different velocities. Gas is composed of very small particles called molecules. A small size of this size allows the total volume of individual gas molecules added to be negligible compared to the volume of the smallest open ball containing all molecules. This is the same as indicating that the average distance of separated gas particles is larger than that size.

According to the theory of motion molecules, the average kinetic energy of gas particles is proportional to the absolute temperature of the gas. This can be expressed by the following expression. Where k is the Boltzmann constant. The Boltzmann constant is simply the gas constant R divided by the Avogadro constant (NA). The top row of some terms indicates that they are average values. This type of equation shows that the root mean square velocity of gas molecules is also related to the molar mass of the material. Comparing the two different molar masses of the gas at the same temperature shows that even with the same average kinetic energy the gas with lower molar mass has a higher root mean square velocity.