Absolute Zero

Key Questions

  • Answer:

    It is the point at which particle motion stops for monatomic ideal gases. However, molecules will still vibrate.


    All temperatures above absolute zero will cause particles in any material to move/vibrate slightly, as temperature gives particles Kinetic energy, according to the equipartition theorem for monatomic ideal gases:


    #k_B# = Boltzmann's constant = #1.38065 times 10^-23 J//K#
    #T# = absolute temperature (Kelvin)

    At absolute zero, #T = "0 K"#, so there is effectively no average kinetic energy of the molecules. (although the state of absolute zero is more of a concept as it has not yet been achieved). This means that particle motion ceases in monatomic gases.

    Absolute zero is also the foundation for the Kelvin scale, as #"0 K" = -273.15^@ "C"# is the coldest that you can ever hope to get.

  • Absolute zero is the temperature at which enthalpy and entropy of ideal gas reaches zero.

    In Kelvin scale this temperature is taken as #0# Kelvin.