Balmer series سری ِ بالمر seri-ye Bâlmer (#)
Fr.: série de Balmer A series of hydrogen → spectral lines
(Hα, Hβ, Hγ, and others) that lies in the visible
portion of the spectrum and results when electrons from upper
→ energy levels (n > 2) undergo
→ transition to n = 2.
Historically, Balmer emission lines (mainly Hα) from ionized nebulae were
first observed by O. Struve and C. T. Elvey (1938, ApJ 88, 364). This was an
important indication of the existence of hydrogen, in the ionized
state, in the → interstellar medium. → Balmer; → series. |