  The research effort prompted by the prediction that SmB$_6$ could be the
first topological Kondo insulator has produced a wealth of new results, though
not all of these seem compatible. A major discrepancy exists between scanning
tunneling microscopy / spectroscopy (STM/S) and angle-resolved photoemission
spectroscopy (ARPES), because the two experimental methods suggest a very
different number of terminations of the (100) surface with different
properties. Here we tackle this issue in a combined STM/S and ARPES study. We
find that two of the well-ordered topographies reported in earlier STM studies
can be associated with the crystal terminations identified using photoemission.
We further observe a reversal of the STM contrast with bias voltage for one of
the topographies. We ascribe this result to a different energy dependence of Sm
and B-derived states, and show that it can be used to obtain element specific
images of SmB$_6$ and identify which topography belongs to which termination.
We finally find STS results to support a modification of the low-energy
electronic structure at the surface that has been proposed as the trivial
origin of surface metallicity in this material.
