This chapter explains how atoms emit and absorb light in the form of spectra. It describes the behavior of electrons when they move between different energy levels inside an atom. The study of atomic spectra helps us understand the structure of atoms and supports important models like Bohr’s atomic theory. It mainly focuses on hydrogen spectrum, spectral lines, and different spectral series, which are very important for board exams.
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🧪 Key Topics Covered
- Atomic Structure and Energy Levels
- Emission and Absorption Spectra
- Hydrogen Spectrum
- Bohr’s Atomic Model
- Spectral Series (Lyman, Balmer, Paschen, etc.)
- Energy Transitions in Atoms
📝 MCQs – Atomic Spectra
1. The spectrum of hydrogen is:
(a) Continuous
(b) Line spectrum ✅
(c) Band spectrum
(d) None
2. In Bohr’s model, electron moves in:
(a) Random paths
(b) Fixed circular orbits ✅
(c) Elliptical paths only
(d) Straight lines
3. Which series lies in ultraviolet region?
(a) Balmer
(b) Paschen
(c) Lyman ✅
(d) Brackett
4. Emission of light occurs when electron:
(a) Gains energy
(b) Loses energy ✅
(c) Stays stable
(d) Stops moving
5. The unit of wavelength is:
(a) Newton
(b) Joule
(c) Meter ✅
(d) Watt
❓ FAQ
Q1: What is atomic spectrum?
Atomic spectrum is the pattern of light emitted or absorbed by atoms when electrons change energy levels.
Q2: What is Bohr’s model?
It is a model of the atom where electrons revolve in fixed orbits with specific energy levels.
Q3: Why is hydrogen spectrum important?
It helps explain atomic structure and supports Bohr’s theory.
Q4: What are spectral series?
They are groups of spectral lines formed due to electron transitions in hydrogen atom.