How can we get four lines from one electron?

To obtain four distinct lines from a single electron, one can utilize a process such as electron transitions in an atom. When an electron is excited to a higher energy level and then returns to a lower energy state, it can emit photons at various wavelengths corresponding to the energy differences between these states. If the electron transitions between multiple energy levels, it can produce multiple spectral lines. Additionally, techniques like fine structure splitting and hyperfine splitting can further increase the number of observable lines from a single electron's transitions.