Molecular Physics

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molecular physics and thermodynamics are sections of physics, studying the bodies occurring in macroscopic processes that are associated with a large number of atoms and molecules contained therein.

molecular physics studies the structure and properties of substances by the molecular - kinetic concepts that are based on the fact that every body is composed of molecules (particles) are in constant random motion.Molecular physics studies the processes of the overall impact of the huge number of molecules.

Thermodynamics studies the general properties of the system (macroscopic) in thermodynamic equilibrium.

study macroscopic processes carried out by two methods:

1. Molecular - kinetic (molecular physics based on this method);

2. thermodynamic, is the basis of thermodynamics.

These methods complement each other.

molecular physics is based on the molecular-kinetic theory, according to which the structure and properties of bodies are explained by the chaotic motion and interaction of molecules, atoms and ions (ie, particles).The experimentally observed properties of objects (eg, pressure) are explained by the impact of the result of the particles, ie the properties of the entire macroscopic system depend on the properties of the particles, particularly their movements and average values ​​of the dynamic characteristics of the particles.Determine the exact location of the particle in space, and its momentum is not possible, but a huge number of them makes good use of the molecular-kinetic (statistical) method, as there are certain regularities in the behavior of the average parameters.

main provisions of the molecular-kinetic theory are:

1. Any substance consists of particles - atoms and molecules, and those of smaller particles;

2. The molecules, atoms and other particles are in continuous chaotic motion;

3. Between the particles there is the force of attraction and repulsion force.

molecular physics are considered: the structure of gases, solids and liquids, their change under external influences (pressure, temperature, electric and magnetic fields), the phenomenon of migration (internal friction, heat conduction, diffusion), the phase transition (evaporation and condensation, crystallizationand melting and the like), phase equilibrium, the critical state of matter.

Thermodynamics studies the thermal processes that are associated with changes in body temperature and state of aggregation.Thermodynamics does not deal with micro-processes, it is involved in the establishment of links between the macroscopic properties of materials.The thermodynamic system is a set of interacting and exchanging energy between themselves and with the outside of macroscopic bodies.The aim of the method is to determine the thermodynamic state in which the thermodynamic system at any time.The collection of characterizing the properties of the system (pressure, temperature, volume) of physical quantities, asking her condition.

thermodynamic processes -change thermodynamic system due to the change of its parameters.

Molecular chemistry - the science of the composition, structure, physical properties of the substance.

physical properties of substances:

1. physical state (solid, gas, liquid);

2. smell;

3. color;

4. density;

5. solubility;

6. electricity - and thermal conductivity;

7. melting point and boiling point.

Any substance composed of atoms and molecules, ions.

atom is the smallest particle of matter consisting of a positively charged nucleus and the negatively charged electron shell.

positive charge carries a proton.Also, the core consists of neutral elementary particles - neurons.The unit of negative charge - the electron.