CBSE 12 Physics Part 2 | 12. ATOMS by Pavan | Learn Smarter with Allrounder.ai
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12. ATOMS

12. ATOMS

The chapter discusses the historical development of atomic models, starting from Thomson's 'plum pudding' model to Rutherford's nuclear model and then to Bohr's quantum model. It outlines the structure and behavior of atoms, detailing the arrangement of electron orbits and the significance of electromagnetic radiation emitted by atoms. The chapter concludes by exploring the limitations of classical models and the need for quantum mechanics in explaining atomic behavior.

11 sections

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Sections

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  1. 12

    This section discusses the atomic structure, including the historical...

  2. 12.1
    Introduction

    This section discusses the evolution of atomic theory, emphasizing key...

  3. 12.2
    Alpha Particle Scattering And Rutherford's Nuclear Model Of The Atom

    This section discusses the discovery of the atomic nucleus through alpha...

  4. 12.2.1
    Alpha-Particle Trajectory

    The section discusses the trajectory of alpha-particles in the context of...

  5. 12.2.2
    Electron Orbits

    This section discusses the Rutherford nuclear model of the atom, focusing on...

  6. 12.3
    Atomic Spectra

    Each element emits a characteristic spectrum of radiation, with hydrogen...

  7. 12.4
    Bohr Model Of The Hydrogen Atom

    The Bohr model provides a quantum mechanical framework for understanding the...

  8. 12.4.1
    Energy Levels

    The energy levels of an atom are quantized, with the electron in the lowest...

  9. 12.5
    The Line Spectra Of The Hydrogen Atom

    The line spectra of hydrogen atoms arise from electron transitions between...

  10. 12.6
    De Broglie's Explanation Of Bohr's Second Postulate Of Quantisation

    Louis de Broglie's hypothesis provided insight into the quantisation of...

  11. 12.7

    This section provides an overview of atomic models, highlighting the...

What we have learnt

  • Atoms are electrically neutral and contain equal amounts of positive and negative charges.
  • Rutherford's model places most of the mass and positive charge in a tiny nucleus, with electrons revolving around it.
  • Bohr's model introduces quantisation in electron orbits and explains atomic spectra with specific energy levels.

Key Concepts

-- Atom
The basic unit of matter, consisting of a nucleus surrounded by electrons.
-- Nuclear Model
Rutherford's model which suggests that an atom has a dense nucleus containing protons and neutrons, with electrons in orbits around it.
-- Quantum Mechanics
A branch of physics that deals with the behavior of matter and light on atomic and subatomic scales.
-- Bohr's Model
A model of the atom that incorporates quantised electron orbits, where electrons do not radiate energy while in certain stable orbits.

Additional Learning Materials

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