Density of hydrogen species inside a photoionized slab. We show the volumetric density of fully ionized hydrogen (blue dashed) and first three levels (1s, 2s, 2p) of neutral hydrogen (solid lines) as a function of depth into the photoionized cloud of Fig. 10. Although most neutral hydrogen in the envelope is in the 1s state, there is a significant population (n_e ≈ 10³ cm⁻³) of electrons in the 2s state, which produces the Balmer break, and resonant scattering of Balmer lines (N(H I, 2s) ≈10¹⁶ cm⁻²). The high column density of free electrons in the same region could be responsible for electron scattering broadening of the Balmer lines.