Ballmer Series
The Ballmer series or the Ballmer line is one of six different series of atoms that appear as the emission lines of hydrogen atoms in atomic physics. The Ballmer series is calculated using the empirical formula, Ballmer equation, found by John Jacob Ballmer in 1885. The visible spectrum of hydrogen appears at four wavelengths of 410 nm, 434 nm, 486 nm, and 656 nm, where photons are emitted by electrons as the quantum number n = 2 shifts from the excited state quantum level. There is also an ultraviolet region Ballmer line with a shorter wavelength than 400 nm.