Recent advances in laser technology have made available to chemists reliable sources of tunable, narrow bandwidth radiation in the ultraviolet and vacuum ultraviolet regions. It has thus become possible to detect with unprecedented sensitivity the diatomic products of bimolecular chemical reactions with resolution of electronic, vibrational, rotational, and even fine structure states. In our laboratory, special attention has been given to studies of the reactivity of optically metastable, electronically excited carbon an0 oxygen atoms, C( D) and 0('D). Examined in detail has been the reaction of C('D) with H2 in which the population of the product CH(v"=O) A doublet states is found to Be inverted. The reaction was further shcown to proceed via a long-lived 'CH collision complex. Extensive studies of 0(±D) + H2 ? OH + H using hydrogen isotopes have demonstrated the importance of angular momentum constraints on the dynamics of HOH collision complex dissociation. Most recently, we have been successful in detecting the CN product of C('D) + NO ? CN + 0('D), evidence for excited oxygen formation having been inferred from the observed CN product energetics. Also to be discussed will be the detection of highly vibrationally excited OH radicals by off-diagonal LIF in the Av = -1i -2 progressions. These experiments provide the first direct evidence that 0('D) + H2 proceeds exclusively by insertion/dissociation with no significant contribution from direct hydrogen abstraction.