Abstract
This paper presents a thermodynamic discussion of homogeneous nucleation. Some serious misconceptions are exposed concerning the proper thermodynamic energy representation that is required for the nucleation problem. The thermodynamic definition of surface tension is found, and the conditions for unstable equilibrium between a liquid drop and its vapor-air environment are developed. A derivation of Kelvin's equation is presented, and the free energy barrier that a cluster of molecules must surmount in order to become a growing drop is discussed. The conventional approach to this problem is compared with our treatment.