Experimental data on the reaction of hydrogen atom abstraction from hydrocarbons, halogenated alkanes, and oxygen-containing compounds by oxygen atoms (50 reactions) are analyzed using the intersecting parabolas model. The influence of five factors on the activation energy of these reactions is determined: the reaction enthalpy, triplet repulsion, electronegativity of atoms of the reaction center, dipole–dipole interaction of the reaction center with polar groups, and π-electrons of neighboring aromatic rings. Increments characterizing the contribution of each factor to the activation energy of the reaction are calculated.