If the entropy of a solid is greater than zero at $T = 0 \ K$,it is called:

The entropy of a perfectly crystalline solid at absolute zero is

At what temperature is the entropy of a perfectly crystalline substance considered to be zero?

The correct statement regarding entropy is,

Fill in the blanks:
$(i)$ The standard enthalpy of formation of any element in its reference state is considered to be $.........$.
$(ii)$ The scientist $.........$ stated that the entropy of a perfectly crystalline substance decreases with a decrease in temperature.
$(iii)$ At absolute zero temperature,the entropy of a perfectly crystalline substance is zero. This statement represents the $.........$ law of thermodynamics.

The entropy of crystalline substances at absolute zero,according to the third law of thermodynamics,should be taken as: