If wavelength of the first line of the Paschen series of hydrogen atom is 720 nm, then the wavelength of the second line of this series is _________ nm. (Nearest integer)
Answer (integer)
492
Solution
$\frac{1}{720}=R \times\left(\frac{1}{9}-\frac{1}{16}\right)$
<br/><br/>
$$
\begin{aligned}
& \Rightarrow R=\frac{9 \times 16}{720 \times 7} \\\\
& \frac{1}{\lambda^{\prime}}=\frac{9 \times 16}{720 \times 7} \times\left(\frac{1}{9}-\frac{1}{25}\right) \\\\
& \lambda^{\prime}=492.18 \mathrm{~nm} \\\\
& \lambda^{\prime}=492 \mathrm{~nm} \text { (nearest integer) }
\end{aligned}
$$
About this question
Subject: Chemistry · Chapter: Atomic Structure · Topic: Bohr's Model
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