Question

The emission spectrum of hydrogen is found to satisfy the expression for the energy change $\Delta E$ (in joules) such that $\Delta E=2.18\times {10}^{-18}(\frac{1}{n_1^2}-\frac{1}{n_2^2})J$ where $n_1=1,2,3,.......,$ and $n_2=2,3,4,.......,$ Then the spectrum lines that correspond to Paschen series have :

• A. $n_1=1and{n}_2=2,3,4$
• B. $n_1=3and{n}_2=4,5,6$
• C. $n_1=1and{n}_2=3,4,5$
• D. $n_1=2and{n}_2=3,3,5$

Answer 1

Answer: (B)

$n_1=3and{n}_2=4,5,6$

The spectrum lines that correspond to Paschen series have
$n_1=3$ and $n_2=4,5,6$.
These lines belong to infrared region.