Atomically-thin sheets of semiconductors have been of immense interest since the Nobel-Prize-winning discovery of graphene or two-dimensional (2D) carbon. Such materials represent the ultimate limit of “scaling” to small sizes, of vital importance in the semiconductor device industry. A particularly exciting recent (2017) finding is that the elemental semiconductor tellurium can be created in 2D sheets, with highly mobile electrons. In this work, University of Minnesota investigators in MRSEC IRG-1 applied “electrolyte gating” to this new material, using the motion of ions to control electronic properties. A transition from semiconductor to metal was found, enabling mapping of the electronic properties of “tellurene” over an extraordinary range. This work highlights not only the potential of tellurene for electronic devices, but also the general power of electrolyte gating (an IRG-1 focus) in 2D materials research.