English: A schematic "roadkill" diagram of the ethanium cation (positive ion) C₂H₇⁺, also called "protonated ethane". It is a carbocation, one of the simples saturated "onium" ions (after methanium, CH₅⁺. It may be viewed as being to ethane what hydrazinium is to hydrazine. The structure of molecule was disputed for a long time, but it was eventually agreed that one of the hydrogens is bridging the two carbons, forming a 2-electron 3-center "non-classical" bond. The charge is distributed symmetrically; I do not know whether it is between the two carbons or over the hydrogens as well. The other hydrogens are not planar.