A mathematical model examining the dynamic behavior of an aerosol undergoing simultaneous particle inception and coagulation or surface growth reactions and coagulation is presented. A bimodal configuration of the distribution function is used to formulate the problem when particle inception mechanisms arc present. Both modes of the distribution are assumed to be of a log-normal form with time varying properties. The model requires knowledge ofthe specific surface growth rate as a function of time, and is potentially applicable for studying aerosols where the surface growth reactions do not coexist with the particle inception mechanisms. The model is used to simulate the time evolution of a soot aerosol inside a flame environment and some important conclusions are drawn related to this problem.