Reactions of neutral, ground-state yttrium atoms with formaldehyde, acetaldehyde, and acetone (Y+RR'CO, where R,R'=H,CH3) were studied in crossed molecular beams. At collision energies greater than 24 kcal/mol, four product channels were observed corresponding to elimination of CO, H-2, H, and nonreactive scattering. For the dominant CO elimination channel, a large fraction (34%-41%) of the available energy appeared as kinetic energy of the products. RRKM modeling indicated this was a result of two factors: a large potential energy barrier for R-' migration leading to (R)(R')YCO and dissociation of this complex prior to complete energy randomization. The CM angular distributions were all forward-backward symmetric, indicating the existence of at least one long-lived reaction intermediate. The angular distributions ranged from being quite forward-backward peaking for the Y+H2CO reaction to isotropic for Y+(CH3)(2)CO. A simple equation is derived based on statistical complex theory that relates the shape of the CM angular distributions to the structure of the dissociating complex.