This Presidential Young Investigator Award, part of the Experimental Physical Chemistry Program, supports research in the area of chemical reaction dynamics. The purpose of this research project is to systematically study the reactivity of energetic molecules, using state-specific methods. A tunable excimer laser in conjunction with a dye laser will be used to excite nitric oxide to a higher excited vibronic state. The reaction products will be observed on a single collision basis using pulsed lasers to measure reaction probability as a function of each reactant quantum number. The role of spin-orbit interactions on the reaction probability will be investigated.