Question

A hydrogen atom sample in the ground state is excited by monochromatic light radiation of wavelength l Å. The resulting spectrum consists of maximum 15 different lines what is l ? (R_H = 109677 cm^–1)

• A. 937.3 Å
• B. 1025Å
• C. 1236 Å
• D. None of these

Answer 1

Answer: (A)

937.3 Å

Answer 2

Total number of spectral line = $\frac{1}{2}$ (n) (n – 1)

= 15 Ž n = 6

So, electron is exited from n = 1 to n = 6

Therefore

$\frac{1}{\lambda} = R_{H}\left\lbrack \frac{1}{n_{1}^{2}}–\frac{1}{n_{2}^{2}} \right\rbrack$

l = 937.3 Å