The energy barriers for the two main types of this process differ by the multiplicative factor “2, minus 3 cosine theta, plus cosine cubed theta, all over 4.” The change in volume Gibbs free energy is inversely proportional to the critical radius for this process; objects smaller than that radius fail to undergo (15[1])this process and are called “embryos.” On a specific S-shaped graph of heat flux vs temperature, the “transition” regime separates the “film” regime from a regime named for this process. Because the (*) heterogeneous form of this process is more efficient, many “sites” for this process are provided by Teflon-coated calcium carbonate chips to facilitate calm (-5[1])boiling. For 10 points, name this first step (10[1])in the formation of a new phase, exemplified by formation of bubbles in a heated liquid. ■END■ (10[1])