Match List-I with List-IIList-IList-IISpectral LinesRegion(A) Lyman S…

The correct answer is Option (2) → (A) - (IV), (B) - (III), (C) - (I), (D) - (II)

Each series of the hydrogen spectrum is named after the lower level n_f on which the electron lands. The higher this level, the smaller the energy gaps, so the photons have less energy and longer wavelength.

    \( \displaystyle \frac{1}{\lambda} = R\left(\frac{1}{n_f^{2}} - \frac{1}{n_i^{2}}\right) \)

(A) Lyman Series — this matches (IV) Ultraviolet Region. Transitions end on n = 1, the largest energy gaps, giving wavelengths from about 91 nm to 122 nm.

(B) Balmer Series — this matches (III) Visible Region. Transitions end on n = 2; its first lines (656 nm, 486 nm, 434 nm, 410 nm) are the visible lines of hydrogen.

(C) Paschen Series — this matches (I) Primarily near infrared Region. Transitions end on n = 3, with wavelengths from about 0.82 μm to 1.87 μm, just beyond the red end of the visible spectrum.

(D) Brackett Series — this matches (II) Primarily middle infrared Region. Transitions end on n = 4, with still longer wavelengths, from about 1.46 μm to 4.05 μm.

Note: This question is from the pre-rationalised NCERT book (2022-23). The topic was removed from the latest NCERT book (2026-27), but it is still in the CUET 2026 syllabus, so do not skip it.

NCERT (Pre-rationalised edition, 2022-23):
Spectral Series – “… In 1885, the first such series was observed by a Swedish school teacher Johann Jakob Balmer (1825–1898) in the visible region of the hydrogen spectrum. This series is called Balmer series (Fig. 12.6).”

Spectral Series – “… The Lyman series is in the ultraviolet, and the Paschen and Brackett series are in the infrared region.”