CBSE 12 Physics Part 2 | 12. ATOMS by Pavan | Learn Smarter with Allrounder.ai
K12 Students

Academics

AI-Powered learning for Grades 8–12, aligned with major Indian and international curricula.

Professionals

Professional Courses

Industry-relevant training in Business, Technology, and Design to help professionals and graduates upskill for real-world careers.

Games

Interactive Games

Fun, engaging games to boost memory, math fluency, typing speed, and English skills—perfect for learners of all ages.

Typing
Memory
Math
English Adventures
Knowledge
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.

Enroll to start learning

You’ve not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.

Sections

  • 12

    Atoms

    This section discusses the atomic structure, including the historical development from Thomson's to Rutherford's models and the introduction of Bohr's model, highlighting the quantized nature of electron orbits.

    Learning Practice

  • 12.1

    Introduction

    This section discusses the evolution of atomic theory, emphasizing key contributions by J. J. Thomson and Ernest Rutherford, and introduces the fundamental structure of the atom.

    Learning Practice

  • 12.2

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

    This section discusses the discovery of the atomic nucleus through alpha particle scattering experiments, leading to Rutherford's nuclear model of the atom.

    Learning Practice

  • 12.2.1

    Alpha-Particle Trajectory

    The section discusses the trajectory of alpha-particles in the context of their scattering by nuclei, leading to insights about atomic structure.

    Learning Practice

  • 12.2.2

    Electron Orbits

    This section discusses the Rutherford nuclear model of the atom, focusing on the dynamics of electron orbits around the positively charged nucleus.

    Learning Practice

  • 12.3

    Atomic Spectra

    Each element emits a characteristic spectrum of radiation, with hydrogen exemplifying this principle through its distinct emission and absorption line spectra.

    Learning Practice

  • 12.4

    Bohr Model Of The Hydrogen Atom

    The Bohr model provides a quantum mechanical framework for understanding the hydrogen atom's structure, introducing quantized orbits for electrons and explaining atomic spectra.

    Learning Practice

  • 12.4.1

    Energy Levels

    The energy levels of an atom are quantized, with the electron in the lowest energy state (ground state) being most stable.

    Learning Practice

  • 12.5

    The Line Spectra Of The Hydrogen Atom

    The line spectra of hydrogen atoms arise from electron transitions between energy levels, leading to the emission of distinct wavelengths of light.

    Learning Practice

  • 12.6

    De Broglie's Explanation Of Bohr's Second Postulate Of Quantisation

    Louis de Broglie's hypothesis provided insight into the quantisation of angular momentum in atomic models, linking wave-particle duality to Bohr's second postulate.

    Learning Practice

  • 12.7

    Summary

    This section provides an overview of atomic models, highlighting the contributions of J.J. Thomson, Ernest Rutherford, and Niels Bohr in the understanding of atomic structure.

    Learning Practice

References

NCERT Study Material

Class Notes

Memorization

What we have learnt

  • Atoms are electrically neut...
  • Rutherford's model places m...
  • Bohr's model introduces qua...

Final Test

Revision Tests