Concept: The hydrogen spectrum is organized into distinctive series based on the final orbital (\( p \)) that an electron transitions to. The visible light region is narrow (400-700 nm).
Formula:$$ \lambda = \frac{hc}{\Delta E} $$
Solution:- The Balmer series is strictly defined by electrons falling from higher orbits down to the second orbit (\( p = 2 \)).
- The energy gaps for these specific transitions (e.g., \( n=3 \to 2 \), \( n=4 \to 2 \)) perfectly correspond to photons with wavelengths in the 400 nm to 700 nm range.
- This range is exclusively the Visible region of light for humans.
Why other options are incorrect:Lyman (C) drops to \( p=1 \), releasing massive energy as UV radiation. Paschen (D) and Brackett (B) drop to \( p=3 \) and \( p=4 \), releasing smaller energy amounts as invisible Infrared radiation.
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