Question

The third line of the Balmer series in the emission spectrum of the hydrogen atom is due to the transition from the :

• A. fourth Bohr orbit to the first Bohr orbit
• B. fifth Bohr orbit to the second Bohr orbit
• C. sixth Bohr orbit to the third Bohr orbit
• D. seventh Bohr orbit to the third Bohr orbit.

Answer 1

Answer: (B)

fifth Bohr orbit to the second Bohr orbit

In the atomic emission spectra of the hydrogen atom, the emission lines from an excited state $n^{th}$ Bohr orbit ($n>2$) to second Bohr orbit ($n=2$) is called Balmer series. Thus emission from $n>2$ to $n=2$ constitutes the various spectral lines of the Balmer series.

For the third line of Balmer series the transition should take place from $n=2+3=5$ to $n=2$ Bohr orbit i.e. from fifth Bohr orbit to second Bohr orbit.