Equipartition Theorem (Thermal Physics)

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SUMMARY

The discussion confirms that the formula 3/2kT = K (ave) accurately represents the average kinetic energy per atom in a monatomic gas, while 5/2kT = K (ave) applies to diatomic molecules. This is derived from the principle that the average energy per degree of freedom is 1/2kT. Additionally, it is established that the equipartition theorem fails at low temperatures when kT is less than the energy spacing in a degree of freedom, resulting in certain degrees of freedom becoming inactive.

PREREQUISITES
  • Understanding of the Equipartition Theorem
  • Familiarity with Boltzmann Constant (k)
  • Knowledge of kinetic energy concepts (K)
  • Basic principles of thermal physics
NEXT STEPS
  • Study the implications of the Equipartition Theorem in various gas types
  • Explore the effects of low temperatures on molecular behavior
  • Investigate the relationship between energy spacing and degrees of freedom
  • Learn about the statistical mechanics underpinning thermal physics
USEFUL FOR

Students and professionals in thermal physics, physicists studying gas behavior, and anyone interested in the statistical mechanics of energy distribution in gases.

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I just wanted to know whether the following formula 3/2kT=K (ave) demonstrates the average kinetic energy per atom in a monatomic gas.
And then if 5/2kT=K (ave) demonstrates the average kinetic energy per diatomic molecule.

This comes from the fact that the average energy per degree of freedom is 1/2kT.

Note k(lowercase) denotes Boltzmann Constant, and K (uppercase) denotes kinetic energy.
 
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Yes, you are correct. The equipartition theorem breaks down at low temperatures when the energy kT is smaller than the energy spacing in a degree of freedom. It doesn't have enough energy to make that jump, so that degree of freedom becomes frozen out.
 

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