Scaling law for asymptotic cross section: Electron-hydrogen collisions

1s → nlm excitations of hydrogen, for arbitrary n, l, m, by electron impact have been investigated within the framework of second-order Born approximation in the momentum space by taking into account the effect of exchange. Scattering amplitude has been derived in a closed form. We have made a detailed study on the total cross sections for intermediate and high energies of the incident electron. A simple law has been presented for obtaining asymptotic cross sections for excitation into different angular momentum states.