Question

Can one consider the temperatures 20 and 30 K as low for a crystal whose heat capacities at these temperatures are equal to 0.226 and 0.760 J/(mol- K)?

Answer 1

At low temperatures C∝T³. This is also a test of the “ lowness ” of the temperature We see that 

Thus T³ law is obeyed and T₁, T₂ can we regarded low.