Line spectrum of hydrogen: emission and absorption (visible Balmer lines)हाइड्रोजन का रेखा स्पेक्ट्रम: उत्सर्जन और अवशोषण (दृश्य बामर रेखाएँ)Line spectrum of hydrogen: emission and absorption (visible Balmer lines)

NCERT Fig 12.5 · Class 12 Physics · Chapter 12 · interactive diagram

Parts and what they mean

• Emission line spectrum (उत्सर्जन रेखा स्पेक्ट्रम) — Hydrogen gas excited at low pressure (e.g. by an electric discharge) gives only certain wavelengths: bright lines on a dark background — a “fingerprint” of hydrogen.
• Absorption spectrum (अवशोषण स्पेक्ट्रम) — White light through cool hydrogen: dark lines appear at exactly the same wavelengths as the emission lines.
• Hα line, 656.3 nm (red) (Hα रेखा, 656.3 nm (लाल)) — Electron jumps n = 3 → n = 2. Photon energy 1.89 eV.
• Hβ line, 486.1 nm (blue-green) (Hβ रेखा, 486.1 nm (नीला-हरा)) — Electron jumps n = 4 → n = 2. Photon energy 2.55 eV.
• Hγ line, 434.1 nm (blue-violet) (Hγ रेखा, 434.1 nm (नीला-बैंगनी)) — Electron jumps n = 5 → n = 2. Photon energy 2.86 eV.
• Hδ line, 410.2 nm (violet) (Hδ रेखा, 410.2 nm (बैंगनी)) — Electron jumps n = 6 → n = 2. Photon energy 3.02 eV.
• Series limit 364.6 nm (श्रेणी सीमा 364.6 nm) — The lines crowd together towards 364.6 nm (n = ∞ → 2), in the ultraviolet.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 12.5. Report a mistake