Structure Of Atom Question 11

Question 11 - 2024 (30 Jan Shift 2)

Number of spectral lines obtained in $He^{+}$spectra, when an electron makes transition from fifth excited state to first excited state will be

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Answer (10)

Solution

$5^{\text {th }}$ excited state $\Rightarrow n _1=6$

$1^{\text {st }}$ excited state $\Rightarrow n _2=2$

$\Delta n=n _1-n _2=6-2=4$

Maximum number of spectral lines

$=\frac{\Delta n(\Delta n+1)}{2}=\frac{4(4+1)}{2}=10$