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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Lyman series

The hydrogen lines that end on (emission) or start from (absorption) n=1n = 1. The gaps to n=1n = 1 are the largest, so every Lyman line is ultraviolet, from 122 nm (2→12 \to 1) down to the 91.2 nm series limit.

Energy levels of the hydrogen atomn = 1: −2.18 × 10⁻¹⁸ J; n = 2: −5.45 × 10⁻¹⁹ J; n = 3: −2.42 × 10⁻¹⁹ J; n = 4: −1.36 × 10⁻¹⁹ J; n = 5: −8.72 × 10⁻²⁰ J. Arrow from n = 2 to n = 1 (emission).n = ∞0 Jn = 1−2.18 × 10⁻¹⁸ Jn = 2−5.45 × 10⁻¹⁹ Jn = 3−2.42 × 10⁻¹⁹ Jn = 4−1.36 × 10⁻¹⁹ Jn = 5−8.72 × 10⁻²⁰ Jemission

2→12 \to 1, the longest-wavelength Lyman line (122 nm).

Example

3→13 \to 1: 1/λ=(1.097×107)(1−19)=9.75×106 m−11/\lambda = (1.097\times10^{7})(1 - \tfrac19) = 9.75\times10^{6}\ \mathrm{m^{-1}}, so λ=103\lambda = 103 nm (UV).

See alsoBalmer seriesSeries limitUltraviolet (UV)Rydberg equation