In the reflection approximation, the dissociative cross sections of H2 by electron impact for production of H(1s) and H(2s) are accurately computed in the Bethe approximation using highly correlated electronic wave functions. It is found that the calculated Bethe cross sections, expected to be valid only for high-incident electron energies, agree surprisingly well with other theoretical values for low impact energies, where electron exchange must surely be included. The discrepancy between theory and experiment reported for total production of H(2s) at incident energies above 500 eV may be attributed to lack of inclusion in the theoretical model of double excitations, particularly those corresponding to optically forbidden transitions.
