Flexi Says: When a narrow beam of this light was viewed through a prism, the light was separated into four lines of very specific wavelengths. An atomic emission spectrum is the pattern of spectral lines formed when light passes through a prism to separate it into the different frequencies of light it contains. When light from a hydrogen gas discharge tube is passed through a prism, the light is split into four visible lines. Each of these spectral lines corresponds to a different electron transition from a higher energy state to a lower energy state. Every element has a unique atomic emission spectrum.