- $\frac{1}{\lambda_{n_f, n_i}}=R\left(\frac{1}{n_f^2}-\frac{1}{n_i^2}\right)$
- Balmer: $n_f=2, \quad n_i=3 \rightarrow $ Straight line
- Lyman: $\quad n_f=1, \quad n_i=2$
- $ \frac{1}{\lambda_{2,3}}=\frac{5 R}{36} $
- $\frac{1}{\lambda_{1,2}}=\frac{3 R}{4}$
- $\begin{aligned} & \lambda_{1,2}=\frac{5}{27} \times \lambda_{2,3} \\ & \approx 1210 \mathring{A}\end{aligned}$
![image](https://temp-public-img-folder.s3.ap-south-1.amazonaws.com/sathee.prutor.images/subject-images/iitpal/image/Physics-Class-12-Unit-12-Chapter-06-Problem-Solvingin-Quantum-Physics-of-Atoms-Part-1-ztt2akahw2s-8.jpg)