NCERT Solutions for Class 12 Physics Chapter 12 Atoms


NCERT solutions for class 12 Physics chapter 12 Atoms: Do you know that an atom tom is electrically neutral, which tells that atoms contain an equal number of positive and negative charges. The NCERT solutions for class 12 Physics chapter 12 Atoms talk about different models of the atom, their drawback, hydrogen spectra, and Debroglie hypothesis. The theories explained in the NCERT grade 12 Physics chapter 12 Atoms are very important in CBSE board exam point of view. To help you in your preparation we provide  NCERT solutions for class 12 Physics chapter 12 Atoms in detail.

Some of the important formulas of NCERT grade 12 chapter 12 - Atoms are given below.

  • The various series in line spectrum of atomic hydrogen are:   


According to Bohr’s postulates for stationary orbit angular momentum


         Where n is the quantum number

  • The total energy of the electron in the stationary states of the hydrogen atom in electronvolt is given by



Where ‘h’ is Planck's constant and mv is the momentum. This relation can be modified in terms of the kinetic energy of the particle. Try to derive it yourself.

The main content headings of NCERT class 12 physics chapter 12 are:

12.1 Introduction

12.2 Alpha-particle Scattering And Rutherford’s Nuclear Model Of Atom

12.2.1 Alpha-particle Trajectory

12.2.2 Electron Orbits

12.3 Atomic Spectra

12.3.1 Spectral Series

12.4 Bohr Model Of The Hydrogen Atom

12.4.1 Energy Levels

12.5 The Line Spectra Of The Hydrogen Atom

12.6 De Broglie’s Explanation Of Bohr’s Second Postulate Of Quantisation

The detailed solutions of NCERT solutions for class 12 Physics chapter 12 Atoms are given below:

Q- 12.1 Choose the correct alternative from the clues given at the end of the each statement: (a) The size of the atom in Thomson’s model is .......... the atomic size in Rutherford’s model. (much greater than/no different from/much less than.)

Q- 12.2 Suppose you are given a chance to repeat the alpha-particle scattering experiment using a thin sheet of solid hydrogen in place of the gold foil. (Hydrogen is a solid at temperatures below 14 K.) What results do you expect?


View all solved exercise questions of class 12 Physics chapter 12 Atoms here.

NCERT Solutions for Class 12 Physics- Chapter wise

Chapter 1

Electric Charges and Fields

Chapter 2

Electrostatic Potential and Capacitance

Chapter 3

Current Electricity

Chapter 4

Moving charges and magnetism

Chapter 5

Magnetism and Matter

Chapter 6

Electromagnetic Induction

Chapter 7

Alternating Current

Chapter 8

Electromagnetic Waves

Chapter 9

Ray Optics and Optical Instruments

Chapter 10

Wave Optics

Chapter 11

Dual nature of radiation and matter

Chapter 13


Chapter 14

Semiconductor Electronics: Materials, Devices and Simple Circuits

NCERT Solutions for Class 12


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