Question

Total number of spectral lines in U.V. region, during transition from $5^{th}$ excited state to $1^{st}$ excited state of an electron in hydrogen would be:

• A. 10
• B. 3
• C. 4
• D. Zero

Answer 1

The correct option is D Zero

The $1^{st}$ excited state means that $n_1=2$. The $5^{th}$ excited state means that $n_2=6$. An electron will transit from the $6^{th}$ level to the $2^{nd}$ level, which is in Balmer Series i.e. visible range of the spectrum. Since there are no transitions upto n = 1, so no line will appear in Lyman Series i.e. U.V. region.