What is the distinction between thermal and internal energy?

In summary, thermal energy refers to the internal energy present in a system due to only its temperature. Internal energy is separated in scale from the macroscopic ordered energy associated with moving objects; it refers to the invisible energy on the atomic and microscopic molecular scale.
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TT0
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What is the difference? I read that thermal energy includes both kinetic and potential energy but isn't that what internal energy is?

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I think there are actually no differences between the two terms. Both internal energy and thermal energy of a system refers to the sum of KE and PE, and both are primarily determined by the collisions and interactions between the atoms and molecules in the system.
However, internal energy should be a more general term than thermal energy. In terms of thermodynamics, the term thermal energy would be used to replace tge term internal energy.
 
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It is just a matter of definition. Thermal energy is primarily defined as the internal energy of a system. Then, thermal energy can be referred as a form of internal energy.
 
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TT0 said:
What is the difference? I read that thermal energy includes both kinetic and potential energy but isn't that what internal energy is?
In thermodynamics , thermal energy refers to the internal energy present in a system due to only to its temperature.

It is often most convenient and precise to think of heat as the transfer of energy,
Heat and work depend on the path of transfer and are not state functions, whereas internal energy is a state function.

Internal energy is defined as the energy associated with the random motion of molecules.

It is separated in scale from the macroscopic ordered energy associated with moving objects; it refers to the invisible on the atomic and microscopic molecular scale.

An example- a glass of water sitting on a table at room temperature has no apparent energy.
. But on the microscopic scale it can be seen as mass of high speed molecules traveling at hundreds of meters per second.
If the water were tossed across the room, this microscopic energy would not necessarily be changed when we superimpose a large scale motion on the water as a whole. so it is state function .

see wiki/hyperphysics site for a discussion.<http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/inteng.html>
 
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I see thanks
 

FAQ: What is the distinction between thermal and internal energy?

1. What is the difference between thermal and internal energy?

Thermal energy is the kinetic energy of molecules in a substance due to its temperature, while internal energy is the total energy of all molecules in a substance, including both kinetic and potential energy.

2. Can thermal energy be converted into internal energy?

Yes, thermal energy can be converted into internal energy through processes such as conduction, convection, and radiation.

3. How are thermal and internal energy related?

Thermal energy is a component of internal energy, and the two are directly proportional to each other. An increase in thermal energy leads to an increase in internal energy.

4. Is there a limit to the amount of thermal and internal energy a substance can have?

Yes, there is a limit to the amount of thermal and internal energy a substance can have. This limit is known as the absolute zero, which is the lowest possible temperature where all molecular motion stops and there is no thermal or internal energy.

5. How does the transfer of thermal energy affect the internal energy of a substance?

The transfer of thermal energy from one substance to another can increase or decrease the internal energy of a substance, depending on the direction of the transfer. For example, when a cold object is placed in contact with a warm object, heat transfer occurs from the warm object to the cold object, increasing the internal energy of the cold object.

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