What is a hydrogen ion

It has the formula of H3O + the three is a subscript

Here are a few facts about hydrogen ion:

•••Hydrogen ion is only the nucleus of a hydrogen atom separated from its accompanying electron.

•••The hydrogen nucleus is made up of a particle carrying a unit positive electric charge, called a proton.

•••The isolated hydrogen ion, represented by the symbol H +, is therefore customarily used to represent a proton.