Thermodynamics and statistical mechanics definition
Answers
Answered by
0
THERMODYNAMICS
Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy. In particular, it describes how thermal energy is converted to and from other forms of energy and how it affects matter.
Thermal energy is the energy a substance or system has due to its temperature, i.e., the energy of moving or vibrating molecules, according to the Energy Education website of the Texas Education Agency. Thermodynamics involves measuring this energy, which can be "exceedingly complicated," according to David McKee, a professor of physics at Missouri Southern State University. "The systems that we study in thermodynamics … consist of very large numbers of atoms or molecules interacting in complicated ways. But, if these systems meet the right criteria, which we call equilibrium, they can be described with a very small number of measurements or numbers. Often this is idealized as the mass of the
system, the pressure of the system, and the volume of the system, or some other equivalent set of numbers. Three numbers describe 1026 or 1030 nominal independent variables."
Temperature
The amount of heat transferred by a substance depends on the speed and number of atoms or molecules in motion, according to Energy Education. The faster the atoms or molecules move, the higher the temperature, and the more atoms or molecules that are in motion, the greater the quantity of heat they transfer.
Temperature is "a measure of the average kinetic energy of the particles in a sample of matter, expressed in terms of units or degrees designated on a standard scale," according to the American Heritage Dictionary. The most commonly used temperature scale is Celsius, which is based on the freezing and boiling points of water, assigning respective values of 0 degrees C and 100 degrees C. The Fahrenheit scale is also based on the freezing and boiling points of water which have assigned values of 32 F and 212 F, respectively.
Scientists worldwide, however, use the Kelvin (K with no degree sign) scale, named after William Thomson, 1st Baron Kelvin, because it works in calculations. This scale uses the same increment as the Celsius scale, i.e., a temperature change of 1 C is equal to 1 K. However, the Kelvin scale starts at absolute zero, the temperature at which there is a total absence of heat energy and all molecular motion stops. A temperature of 0 K is equal to minus 459.67 F or minus 273.15 C.
STATISTICAL THERMODYNAMICS
Thermodynamics describes the behavior of systems containing a large number of particles. These systems are characterized by their temperature, volume, number and the type of particles. The state of the system is then further described by its total energy and a variety of other parameters including the entropy. Such a characterization of a system is much simpler than trying to keep track of each particle individually, hence its usefulness. In addition, such a characterization is general in nature so that it can be applied to mechanical, electrical and chemical systems.
The term thermodynamics is somewhat misleading as one deals primarily with systems in thermal equilibrium. These systems have constant temperature, volume and number of particles and their macroscopic parameters do not change over time, so that the dynamics are limited to the microscopic dynamics of the particles within the system.
Statistical thermodynamics is based on the fundamental assumption that all possible configurations of a given system, which satisfy the given boundary conditions such as temperature, volume and number of particles, are equally likely to occur. The overall system will therefore be in the statistically most probable configuration. The entropy of a system is defined as the logarithm of the number of possible configurations multiplied with Boltzmann’s constant. While such definition does not immediately provide insight into the meaning of entropy, it does provide a straightforward analysis since the number of configurations can be calculated for any given system.
Classical thermodynamics provides the same concepts. However, those were obtained through experimental observation. The classical analysis is therefore more tangible compared to the abstract mathematical treatment of the statistical approach.
The study of semiconductor devices requires some specific results, which naturally emerge from statistical thermodynamics. In this section, we review basic thermodynamic principles as well as some specific results. These include the thermal equilibrium concept, the thermodynamic identity, the basic laws of thermodynamics, the thermal energy per particle, the Fermi function and the thermal voltage
Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy. In particular, it describes how thermal energy is converted to and from other forms of energy and how it affects matter.
Thermal energy is the energy a substance or system has due to its temperature, i.e., the energy of moving or vibrating molecules, according to the Energy Education website of the Texas Education Agency. Thermodynamics involves measuring this energy, which can be "exceedingly complicated," according to David McKee, a professor of physics at Missouri Southern State University. "The systems that we study in thermodynamics … consist of very large numbers of atoms or molecules interacting in complicated ways. But, if these systems meet the right criteria, which we call equilibrium, they can be described with a very small number of measurements or numbers. Often this is idealized as the mass of the
system, the pressure of the system, and the volume of the system, or some other equivalent set of numbers. Three numbers describe 1026 or 1030 nominal independent variables."
Temperature
The amount of heat transferred by a substance depends on the speed and number of atoms or molecules in motion, according to Energy Education. The faster the atoms or molecules move, the higher the temperature, and the more atoms or molecules that are in motion, the greater the quantity of heat they transfer.
Temperature is "a measure of the average kinetic energy of the particles in a sample of matter, expressed in terms of units or degrees designated on a standard scale," according to the American Heritage Dictionary. The most commonly used temperature scale is Celsius, which is based on the freezing and boiling points of water, assigning respective values of 0 degrees C and 100 degrees C. The Fahrenheit scale is also based on the freezing and boiling points of water which have assigned values of 32 F and 212 F, respectively.
Scientists worldwide, however, use the Kelvin (K with no degree sign) scale, named after William Thomson, 1st Baron Kelvin, because it works in calculations. This scale uses the same increment as the Celsius scale, i.e., a temperature change of 1 C is equal to 1 K. However, the Kelvin scale starts at absolute zero, the temperature at which there is a total absence of heat energy and all molecular motion stops. A temperature of 0 K is equal to minus 459.67 F or minus 273.15 C.
STATISTICAL THERMODYNAMICS
Thermodynamics describes the behavior of systems containing a large number of particles. These systems are characterized by their temperature, volume, number and the type of particles. The state of the system is then further described by its total energy and a variety of other parameters including the entropy. Such a characterization of a system is much simpler than trying to keep track of each particle individually, hence its usefulness. In addition, such a characterization is general in nature so that it can be applied to mechanical, electrical and chemical systems.
The term thermodynamics is somewhat misleading as one deals primarily with systems in thermal equilibrium. These systems have constant temperature, volume and number of particles and their macroscopic parameters do not change over time, so that the dynamics are limited to the microscopic dynamics of the particles within the system.
Statistical thermodynamics is based on the fundamental assumption that all possible configurations of a given system, which satisfy the given boundary conditions such as temperature, volume and number of particles, are equally likely to occur. The overall system will therefore be in the statistically most probable configuration. The entropy of a system is defined as the logarithm of the number of possible configurations multiplied with Boltzmann’s constant. While such definition does not immediately provide insight into the meaning of entropy, it does provide a straightforward analysis since the number of configurations can be calculated for any given system.
Classical thermodynamics provides the same concepts. However, those were obtained through experimental observation. The classical analysis is therefore more tangible compared to the abstract mathematical treatment of the statistical approach.
The study of semiconductor devices requires some specific results, which naturally emerge from statistical thermodynamics. In this section, we review basic thermodynamic principles as well as some specific results. These include the thermal equilibrium concept, the thermodynamic identity, the basic laws of thermodynamics, the thermal energy per particle, the Fermi function and the thermal voltage
Similar questions