Shocks and instabilities in the partially ionised solar atmosphere

The low solar atmosphere is composed of mostly neutral particles, but the importance magnetic field for understanding observed dynamics means that interactions between charged and particles play a very important role in controlling macroscopic fluid motions. As exchange momentum fluids, essential to effectively feel Lorentz force, through collisional interactions, relative timescale these dynamic determines whether single-fluid model or, when frequency higher, more detailed two-fluid appropriate. However, as many MHD phenomena fundamentally contain multi-time-scale processes, even large-scale, long-timescale motions can have an physical contribution from processes. In this review we will focus on models, looking detail at two areas where nature physics easily develop: shock-waves instabilities. We then connect ideas observations attempting diagnose behaviour atmosphere, suggesting some ways forward bring simulations closer together.