Spectral Series of the Hydrogen Atom

This diagram of the energy levels of the hydrogen atom shows the allowed transitions between them. The ground state at -13.6 eV is not shown, nor are sublevels for each principal quantum number . The energies are listed at the right and the quantum numbers are on the left. The first series of spectral lines was discovered by Johan Jacob Balmer in 1885, followed by other series named after their discoverers.