Solution to task 662 from Chertov´s for extramural stud

Solution to task 662 from Chertov´s for extramural stud

662. Calculate the characteristic Debye temperature ΘD for iron, if at temperature T = 20 K the molar heat capacity of iron is Cm = 0.226 J / K mol. The condition Т << ΘD is considered satisfiable.