= + 4zry The free energy change of a system upon nucleation of a spherical solid particle of radius r from a liquid may be expressed as 4 AG=-arAG solid + 3 where AGsolid is the free energy per unit volume of the solid phase relative to the liquid phase, and y is the interfacial energy between the solid and liquid phases and is always positive). Assume that we are in a temperature regime for which AG solid rc and particles with r