Ritz's combination principle

Ritz's combination principle [′rit·səz ‚käm·bə′nā·shən ‚prin·sə·pəl]

(spectroscopy)

The empirical rule that sums and differences of the frequencies of spectral lines often equal other observed frequencies. Also known as combination principle.

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Ritz's combination principle

The empirical rule, formulated by W. Ritz in 1905, that sums and differences of the frequencies of spectral lines often equal other observed frequencies. The rule is an immediate consequence of the quantum-mechanical formula hf = E_i - E_f relating the energy hf of an emitted photon to the initial energy E_i and final energy E_f, of the radiating system; h is Planck's constant and f is the frequency of the emitted light. See Atomic structure and spectra, Energy level (quantum mechanics), Quantum mechanics