Hydrogen can have an infinite number of energy levels, based on the principle of quantum mechanics. These energy levels are represented by the quantum number "n".
A hydrogen atom is the simplest atom that exists in nature, consisting of a single proton and a lone electron. The electron is most likely found in an electron cloud, where it occupies a particular orbital "state" that corresponds to an energy level. In a neutral atom, the electron is found in the "ground state," or the energy level that is closest to the proton. Each energy level contains a specific amount of energy, which is denoted by a negative eV quantity. The energy levels of hydrogen can be obtained by using the general equation E = - E0/n2, where "E" indicates the energy level, "E0" equals 13.6 eV and "n" takes on a range of values from one to infinity.