As you know, all substances in nature have their physical state, one of which is gas.Components of the particles - molecules and atoms - are separated by a distance.However, they are in constant motion freely.This property indicates that the interaction of the particles occurs only at the time of convergence, dramatically increasing the speed of the colliding molecules and their size.This gaseous substance is different from the solid and liquid.
The word "gas" in Greek sounds like "chaos".This perfectly characterizes the movement of particles, which is really random and chaotic.The gas does not form a specific surface, it fills the entire volume available to him.Such a state of matter - the most common in our universe.
laws that determine the properties and behavior of the substance, the easiest to formulate and consider the example of a state in which the relative density of molecules and atoms is low.It was called the "ideal gas".It distance between the particles is greater than the radius of intermolecular interaction forces.
So, the ideal gas - a theoretical model of matter, which is almost completely absent the interaction of particles.For him, there must be the following conditions:
-
very small molecules.
-
not have the force of interaction between them.
-
collision occurs as the collision of elastic balls.
good example of this state of the material gases can be called in which the pressure at a low temperature does not exceed 100 times atmospheric.They are ranked as discharged.
The concept of "ideal gas" made it possible to build a science of molecular-kinetic theory, the findings of which are confirmed in many experiments.According to this teaching are different ideal gases classical and quantum.
first specifications are reflected in the laws of classical physics.Movement of particles in the gas are not dependent on each other, the pressure exerted on the wall is equal to the sum of pulses which are transmitted in a collision the individual molecules in a given time.Their energy is the sum of the combined individual particles.The work of an ideal gas in this case is calculated Clapeyron equation p = nkT.A striking example of this are the laws derived physical scientists such as Boyle, Gay-Lussac, Charles.
If an ideal gas lowers the temperature and increases the density of the particles up to a certain point, increases its wave properties.A transition to the quantum gas at which wavelengths of atoms and molecules is comparable with the distance between them.There are two types of ideal gas:
-
Doctrine Bose and Einstein particles of one species have integer spin.
-
Fermi Dirac statistics: other type of molecules having a half-integer spin.
difference between the classical ideal gas of quantum is that even at absolute zero temperature, energy density and pressure are different from zero.They become more with increasing density.In this case, the particles have a maximum (another name - the boundary) energy.From this perspective, we consider the theory of the structure of stars in those in which a higher density of 1-10 kg / cm3 pronounced law electrons.And where it exceeds 109kg / cm3, the material is converted into neurons.
In metals, the use of the theory in which the classical ideal gas of the quantum, helps to explain much of the metallic properties of the state of matter: the denser particles, so it is closer to the ideal.
When strongly pronounced low temperatures of various substances in liquid and solid states of the collective motion of the molecules can be considered as the work of an ideal gas of weakly excitations.In such cases, the visible contribution to the energy of the body, which particles are added.
