As you know, every body has its own unique structure, which is determined by its chemical composition and structure.At the same time, the particles that make up this structure are mobile, they interact with each other, and therefore have a certain amount of internal energy.The solids of the particles that make up the structure of the body, strong, so their interaction with the particles that make up the structure of other bodies difficult.
Quite differently, it looks in liquids or gases, where molecular bonds are weak, but because the molecules can move freely enough to interact with the particles and other substances.In this case, for example showing the properties of solubility.
So, the internal energy of the gas is a parameter that determines the state of the gas, that is, the energy of thermal motion of its micro-particles, which are the molecules, atoms, nuclei, and so on.. In addition, this concept also characterizes the energy of their interaction.
the transition of the molecule from one state to another, the internal energy of the gas, which is a formula -
for their physical bodies is subject to the dynamics of the internal energy (change) only when the interaction of these bodies with other bodies.At the same time, there are two basic ways to change this: the work (done by the friction, impact, compression, etc.) and heat transfer.The latter method - Heat Transfer -otrazhaet dynamics of change in internal energy when the work is not done, and the energy is transferred, for example, bodies with higher temperature bodies with less its value.
In this case, distinguish these types of heat like:
- thermal conductivity (direct energy exchange particles executing chaotic motion);
- convection (internal energy of the gas flow is transferred to them);
- radiation (energy is transferred by means of electromagnetic waves).
All these processes are recognized by the law of conservation of energy.If this law is considered in relation to the thermodynamic processes occurring in gases, it can be formulated as follows: the internal energy of a real gas - or rather, its change is a cumulative amount of heat that was transferred to it from external sources, and from the work that has beencommitted on the gas.
If we consider the effect of this law (first law of thermodynamics) in relation to an ideal gas, we can see these patterns.In the process, the temperature of which remains constant (isothermal process), the internal energy is also always constant.
Within the isobaric process, which is characterized by changes in the gas temperature, increase or decrease, leading, respectively, to increase or decrease the internal energy of the gas and perform the work.This phenomenon, for example, illustrates the expansion of a gas under heating and the ability of the gas to propel steam aggregates.
When considering the isochoric process in which the setting of its volume remains the same, the internal energy of the gas changes only under the influence of the amount of heat transferred.There
and adiabatic process, which tend to lack of heat transfer gas from external sources.In this case, the value of its internal energy decreases, hence - the gas cools.
