  Extensions have been made recently to the coronal approximation for the
purpose of modelling line emission from carbon and oxygen in the lower solar
atmosphere. The same modelling is used here for other elements routinely
observed in the solar transition region: N, Ne, Mg, Si and S. The modelling
includes the effects of higher densities suppressing dielectronic recombination
and populating long-lived, metastable levels; the presence of metastable levels
typically causes effective ionisation rates to increase and recombination rates
to decrease. Processes induced by the radiation field, namely photo-ionisation
and photo-excitation, have been included, along with charge transfer, which
occurs when electrons are exchanged during atom-ion and ion-ion collisions. The
resulting ion balances are shown, and indicate significant changes compared to
the frequently-employed coronal approximation. The effect on level populations
within ions caused by photo-excitation is also assessed. To give an
illustration of how line emission could be altered by these processes, selected
line contribution functions are presented at the end.
