Balmer Series

The Balmer series is characterized by the electron transitioning from n ЎЭ 3 to n = 2, where n refers to the radial quantum number or principal quantum number of the electron. The transitions are named sequentially by Greek letter: n = 3 to n = 2 is called H-¦Ð', 4 to 2 is H-¦Ð', 5 to 2 is H-¦Ð", and 6 to 2 is H-¦Ð". As the spectral lines associated with this series are located in the visible part of the electromagnetic spectrum, these lines are historically referred to as H-alpha, H-beta, H-gamma and H-delta where H is the element hydrogen.

Balmer Series (Second) (visible light) n=2 limit = 365 nm

n = 3, ¦Ð› = 656.3 nm, ¦Ð', color emitted: red

n = 4, ¦Ð› = 486.1 nm, ¦Ð', color emitted: bluegreen

n = 5, ¦Ð› = 434.1 nm, ¦Ð", color emitted: violet

n = 6, ¦Ð› = 410.2 nm, ¦Ð", color emitted: violet

Although physicists were aware of atomic emissions before 1885, they lacked a tool to accurately predict where the spectral lines should appear. The Balmer equation predicts the four visible absorption/emission lines of hydrogen with high accuracy. Balmer's equation led physicists to find the Lyman, Paschen, and Brackett series which predicted other absorption/emission lines found outside the visible spectrum.

The familiar red H-alpha line of hydrogen which is the transition from the shell n=3 to the Balmer series shell n=2 is one of the conspicuous colors of the universe contributing a bright red line to the spectra of star forming regions.

Later, it was discovered that when the spectral lines of the hydrogen spectrum are examined at very high resolution, they are found to be closely-spaced doublets. This splitting is called fine structure. It was also found that excited atoms could jump to the Balmer series n=2 from orbitals where n was greater than 6 emitting shades of violet.

[edit] Balmer's formula

Balmer noticed that a single number had a relation to every line in the hydrogen spectrum that was in the visible light region. That number was 364.56 nm. When any integer higher than 2 was squared and then divided by itself minus 4, then that number multiplied by 364.56 gave a wavelength of another line in the visible hydrogen spectrum. By this formula he was able to show that certain measurements of lines made in his time by spectroscopy were slightly inaccurate measurements and his formula predicted lines that were later found although had not yet been observed. His number also proved to be the limit of the series.

The formula discovered