Structure Of Atom Question 2

Question 2 - 24 January - Shift 1

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)

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Answer: (492)

Solution:

Formula: Wavelength of Emitted Photon

$\frac{1}{(\lambda_1) _P}=R_H Z^{2}(\frac{1}{9}-\frac{1}{16})$

$\frac{1}{(\lambda_2) _P}=R_H Z^{2}(\frac{1}{9}-\frac{1}{25})$

$\frac{\left(\lambda_2\right) _{\mathrm{P}}}{\left(\lambda _1\right) _{\mathrm{P}}}=\frac{\frac{7}{16 \times 9}}{\frac{16}{25 \times 9}}=\frac{25 \times 7}{16 \times 16}$

$(\lambda _2) _P=\frac{25 \times 7}{16 \times 16} \times 720$