Number of spectral lines obtained in $\mathrm{He}^{+}$ spectra, when an electron makes transition from fifth excited state to first excited state will be
Answer (integer)
10
Solution
<p>$$\begin{aligned}
& 5^{\text {th }} \text { excited state } \Rightarrow n_1=6 \\
& 1^{\text {st }} \text { excited state } \Rightarrow n_2=2 \\
& \Delta n=n_1-n_2=6-2=4
\end{aligned}$$</p>
<p>Maximum number of spectral lines</p>
<p>$=\frac{\Delta \mathrm{n}(\Delta \mathrm{n}+1)}{2}=\frac{4(4+1)}{2}=10$</p>
About this question
Subject: Chemistry · Chapter: Atomic Structure · Topic: Bohr's Model
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