Why is absolute zero important?

1 Answer
Oliver S. · Truong-Son N.
Apr 11, 2018

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

Explanation:

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_(avg)=3/2k_BT#

#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.

Related questions
See all questions in Absolute Zero
Impact of this question
4798 views around the world
You can reuse this answer
Creative Commons License