The Balmer series refers to a set of spectral lines that are produced when an electron in a hydrogen atom transitions from a higher energy level to the second energy level. These transitions emit light in the visible spectrum, resulting in specific wavelengths that correspond to colors. The Balmer series is important in understanding atomic structure and the behavior of electrons. Named after the Swiss physicist Johann Balmer, who formulated the mathematical equation to describe these wavelengths in 1885, the series includes prominent lines such as H-alpha, H-beta, H-gamma, and H-delta. The Balmer series is a key concept in fields like astronomy and spectroscopy, helping scientists analyze the composition of stars and other celestial bodies.