Question

Give reason . Entropy of a substance is taken. As zero at absolute temperature

Answer 1

Entropy is the measure of degree of randomness or disorderness .

At absolute temperature all the molecular motion ceases or stops .

So randomness becomes zero.

Hence, entropy is zero at

Another answer

The third law of thermodynamics states that the entropy of a system at absolute zero is a well-defined constant. This is because a system at zero temperature exists in its ground state, so that its entropy is determined only by the degeneracy of the ground state.