A method has been developed to determine the enthalpy of atom formation in a graphite furnace without invoking the order of reaction. The method is based on the equation In (AT) = −ΔH0/RT + C, whereAis the peak-height absorbance,Tis the absolute temperature, ΔH0is the enthalpy of atom formation which, for highly endothermic reactions, is considered to be equal to the activation energy,RandCare the universal gas constant and the constant of integration, respectively. The plot of In (AT) vs. 1/Tis similar to an Arrhenius-type plot and should yield the activation energy. Atomization mechanisms for eight elements, Cu, Co, Ga, Au, Ni, Fe, Ag, and Al, are proposed by correlating the experimental enthalpy with a very limited set of possible primary reactions. One significant result of this work is that the experimentally observed enthalpy of reaction correlates well with the activation energy, this means no excess energy other than the enthalpy of atomization is involved in the reaction.