ABSTRACT
The third law of thermodynamics is concerned with the entropy of a system as the temperature is reduced to absolute zero. The original statement of the third law was given by Nernst in 1906. Nernst noticed that, in many chemical reactions occurring with no change in the end point temperatures, the value of ΔG decreased while that of ΔH increased. Nernst postulated as his heat theorem that not only did these two quantities become equal at T = 0 but they also approached each other asymptotically. The original Nernst formulation of the third law has subsequently been followed by various other statements which are more in accord with our understanding of modern quantum statistical mechanics. A particularly useful statement of the third law was given by Planck in 1911.
