NCERT Solutions for Class 11 Chemistry, Chapter 2 - Structure of Atom

In this chapter, you will learn about the structure of an atom in detail. As you are already aware of, an atom is the smallest unit of a matter, which is derived from the Greek word ‘a-tomio’ which means ‘indivisible’. The topic of the atom has attracted the attention of various scientists right from the time of early age (400 B.C.) Many Indian and Greek scientists have made numerous important discoveries with regards to ‘Atom’. In this chapter, you’ll also come across various discoveries made by famous scientists such as Thomson, Rutherford and Bohr. Further, in this chapter, you will learn new terms related to atoms such as electrons, protons, neutrons and their characteristics.

Thus, an in-depth study of Class 11 Chemistry NCERT Solutions Chapter 2 will give you a clear understanding of the structure of the atom, which is a crucial topic in chemistry.

Let’s take a look at topics and sub-topics of Class 11 Chemistry Chapter 2, Structure of Atom.

2.1 Discovery of Sub-atomic Particles

2.1.1 Discovery of Electron

2.1.2 Charge to Mass Ratio of Electron

2.1.3 Charge on the Electron

2.1.4 Discovery of Protons and Neutrons

2.2 Atomic Models

2.2.1 Thomson Model of Atom

2.2.2 Rutherford’s Nuclear Model of Atom

2.2.3 Atomic Number and Mass Number

2.2.4 Isobars and Isotopes

2.2.5 Drawbacks of Rutherford Model

2.3 Developments Leading to the Bohr’s Model of Atom

2.3.1 Wave Nature of Electromagnetic Radiation

2.3.2 Particle Nature of Electromagnetic Radiation: Planck’s Quantum Theory

2.3.3 Evidence for the quantized* Electronic Energy Levels: Atomic spectra

2.4 Bohr’s Model for Hydrogen Atom

2.4.1 Explanation of Line Spectrum of Hydrogen

2.4.2 Limitations of Bohr’s Model

2.5 Towards Quantum Mechanical Model of the Atom

2.5.1 Dual Behaviour of Matter

2.5.2 Heisenberg’s Uncertainty Principle

2.6 Quantum Mechanical Model of Atom

2.6.1 Orbitals and Quantum Numbers

2.6.2 Shapes of Atomic Orbitals

2.6.3 Energies of Orbitals

2.6.4 Filling of Orbitals in Atom

2.6.5 Electronic Configuration of Atoms

2.6.6 Stability of Completely Filled and Half Filled Subshells

In Class 11 Chemistry Chapter 2, you will learn –

Section 2.1 – In this section, you’ll learn about the discovery of electrons and some important propositions made by the famous scientist Michael Faraday. You’ll also learn what cathode ray discharge tubes, cathode rays or cathode ray particles and some interesting discoveries made by British physicist J.J. Thomson and R.A. Millikan are.

Section 2.2 – In this section, you will study the main problems faced by scientists after the discovery of sub-atomic particles. You’ll also come across the properties of fundamental particles, the Thomson model of the atom, Rutherford’s famous α–particle scattering experiment and conclusions made by him. You’ll learn what atomic number, mass number, nucleons, isotopes, protium, deuterium, tritium and the limitation of the Rutherford Model is.

Section 2.3 – In this section, you’ll acquire knowledge about two significant developments made in the formulation of Bohr’s model of the atom. You’ll also learn what electromagnetic waves or electromagnetic radiation, explanation given by James Maxwell regarding the behaviour of electrical and magnetic fields are. You’ll come across some properties of electromagnetic waves and learn related terms like electromagnetic spectrum, visible light, speed of light, wavenumber, particle nature of electromagnetic radiation, Planck’s Quantum Theory and more.

Section 2.4 – In this section, you’ll acquire knowledge about Bohr’s model for the hydrogen atom, Principal quantum numbers, Rydberg constant, explanation of line spectrum of hydrogen and drawbacks of Bohr’s Model.

Section 2.5 – In this section, you’ll study about the dual behaviour of matter as proposed by The French physicist, de Broglie and the uncertainty principle as stated by Werner Heisenberg, a German physicist in 1927. You’ll also learn about the significance and effects of the uncertainty principle and the reasons for the failure of the Bohr Model.

Section 2.6 – In this section, you’ll learn what quantum mechanics is, the hydrogen atom and the Schrödinger equation, some crucial features of the Quantum Mechanical Model of Atom and more.

In this chapter, you are provided with several examples with their solutions for clear understanding about Structure of Atom. To know more about NCERT Solutions for Class 11 Chemistry Chapter 2, you should explore the exercises mentioned in this chapter. You can also download the NCERT Solutions for Class 11 Chemistry Chapter 2 PDF, solved by our science experts.