1-20 水素のスペクトル

解答

ライマン系列は n1 = 1 の輝線なので n2 = 2, 3, 4 を順に代入して

n1 = 1, n2 = 2 のとき

\displaystyle \tilde{\nu}= \frac{1}{\lambda} = ({\rm 109680~cm^{-1}})\left(\frac{1}{1^2}-\frac{1}{2^2}\right) =  ({\rm 109680~cm^{-1}}) \times \frac{3}{4}\\ \\ = \rm 82260~cm^{-1}  
\displaystyle \lambda = \rm \frac{1}{82260~cm^{-1}} = 1.2157 \times 10^{-5} cm\\ \\ = \rm 1.2157 \times 10^{-7}~m = 121.57~nm  

n1 = 1, n2 = 3 のとき

\displaystyle \tilde{\nu}= \frac{1}{\lambda} = ({\rm 109680~cm^{-1}})\left(\frac{1}{1^2}-\frac{1}{3^2}\right) =  ({\rm 109680~cm^{-1}}) \times \frac{8}{9}\\ \\ = \rm 97493~cm^{-1}  
\displaystyle \lambda = \rm 1.0257 \times 10^{-7}~m = 102.57~nm  

n1 = 1, n2 = 4 のとき

\displaystyle \tilde{\nu}= \frac{1}{\lambda} = ({\rm 109680~cm^{-1}})\left(\frac{1}{1^2}-\frac{1}{4^2}\right) =  ({\rm 109680~cm^{-1}}) \times \frac{15}{16}\\ \\ = \rm 102825~cm^{-1}  
\displaystyle \lambda = \rm 9.7252 \times 10^{-8}~m = 97.252~nm