-2

Does helium freeze at absolute zero? In theory, it should, since all random motions of particles stops at absolute zero, right?

The_CIA
  • 119
  • 5
  • It actually doesn't. I'm not talking about ordinary pressures, I'm talking about absolute zero at any pressure. – The_CIA Oct 27 '20 at 03:14

1 Answers1

3

Not at atmospheric pressure. You need at least 25 atmospheres pressure to solidify helium-4 and at least 29 atmospheres (0.3 K) for helium-3. See Wikipedia.

At low pressure you fail to solidify the helium because of weak interatomic interactions combined with quantum mechanical zero point energy. Higher pressure favors forming a denser structure with an ordered lattice arrangement, thus a crystalline solid.

Oscar Lanzi
  • 56,895
  • 4
  • 89
  • 175