Question

what is third law of thermodynamics..​

Answer 1

Hi.

here is your answer.

✏ 3rd law of thermodynamics state that,

the entropy of a pure ,perfectly ordered crystalline substance is zero at absolute zero temperature (0K)

Hence at 0K for pure crystalline substance S =0.

hope it helps you ☺

Answer 2

It is defined as the entropy  of  a  pure  and  perfectly  crystalline  substance  is zero at the  absolute 0of a temperature