Question

The emission spectrum of hydrogen is found to satisfy the expression for the energy change $\Delta E$ (in joules) such that $\Delta E=2.18\times10^{-18}\left(\frac{1}{n^{2}_{1}}-\frac{1}{n^{2}_{2}}\right)J$ where $n_1 = 1$, $2$, $3$, $.....$ and $n_2 = 2$, $3$, $4$. The spectral lines corresponds to Paschen series if

• A. $n_1 = 1$ and $n_2 = 2$, $3$, $4$
• B. $n_1 = 3$ and $n_2 = 4$, $5$, $6$
• C. $n_1 = 1$ and $n_2 = 3$, $4$, $5$
• D. $n_1 = 2$ and $n_2 = 3$, $4$, $5$

Answer 1

Answer: (B)

In the emission spectra of hydrogen atom, Paschen series is the one where the transition from higher energy states to third energy state takes place.
i.e. $n_{f}=n_{1}=3$ and $n_{i}=n_{2} > 3$