Answer:
6
Explanation:
[tex]n_1[/tex] = Final energy level = 2
[tex]R_H[/tex] = Rydberg constant = [tex]10967758.3\ \text{m}^{-1}[/tex]
[tex]\lambda[/tex] = Wavelength = 410 nm
From the Rydberg formula we have
[tex]\dfrac{1}{\lambda}=R_H(\dfrac{1}{n_1^2}-\dfrac{1}{n_2^2})\\\Rightarrow n_2=(\dfrac{1}{n_1^2}-\dfrac{1}{\lambda R_H})^{-\dfrac{1}{2}}\\\Rightarrow n_2=(\dfrac{1}{2^2}-\dfrac{1}{410\times 10^{-9}\times 10967758.3})^{-\dfrac{1}{2}}\\\Rightarrow n_2=\pm6.01\approx 6[/tex]
The initial energy level is 6.