The Rydberg constant $R_H \approx 1.097 \times 10^7 \text{ m}^{-1}$. Calculate the wavelength $\lambda$ of a photon in nanometers when $n=2$ to $n=1$ transition occurs using $\frac{1}{\lambda} = R_H(\frac{1}{1^2} - \frac{1}{2^2})$.