A pure crystalline substance has no movement at absolute zero temperature. O 1st Law of Thermodynamics O 3rd Law of Thermodynamics O Law of Absolute Zero 2nd Law of Thermodynamics

3rd Law of Thermodynamics

The correct answer is the third law of thermodynamics.

"The entropy of a perfect crystal is zero when the temperature of the crystal is equal to absolute zero (0 K)."

The temperature scale they refer to is the zero in kelvin degrees, this is what we call absolute zero.

If the entropy is zero, all physic processes stop, and the entropy of the system is minimum and constant.