  We consider relativistic quantum field theory in the presence of an external
electric potential in a general curved space-time geometry. We utilise Fermi
coordinates adapted to the time-like geodesic to describe the low-energy
physics in the laboratory and calculate the leading correction due to the
curvature of the space-time geometry to the Schr\"odinger equation. We then
compute the non-vanishing probability of excitation for a hydrogen atom that
falls in or is scattered by a general Schwarzschild black hole. The photon that
is emitted from the excited state by spontaneous emission extracts energy from
the black hole, increases the decay rate of the black hole and adds to the
information paradox.
