Atomic Models

1. John Dalton’s Atomic Theory:

• Indivisibility of atoms.
• Relative weights of atoms.
• Law of multiple proportions.

References:

• NCERT Chemistry Class 11 (Part I), Chapter 1: Some Basic Concepts of Chemistry.

2. Cathode Rays and Discovery of Electrons:

• Experiments by William Crookes.
• Discovery of electrons by J.J. Thomson.
• Properties and characteristics of cathode rays.

References:

• NCERT Physics Class 12 (Volume I), Chapter 2: Electrostatic Potential and Capacitance.

3. Positive Rays and Identification of Protons:

• Experiments related to positive rays by Eugen Goldstein.
• Identification of protons.
• Properties and characteristics of positive rays.

References:

• NCERT Physics Class 12 (Volume I), Chapter 15: Nuclei.

4. Rutherford’s Gold Foil Experiment:

• Experimental setup and observations.
• Discovery of the atomic nucleus.
• Rutherford’s model of the atom.

References:

• NCERT Physics Class 12 (Volume I), Chapter 15: Nuclei.

5. Rutherford’s Model of the Atom:

• Key features of the nuclear model.
• Central nucleus with protons.
• Mostly empty space in the atom.

References:

• NCERT Physics Class 12 (Volume I), Chapter 15: Nuclei.

6. Nuclear Size and Scattering Experiments:

• Determination of nuclear size.
• Scattering experiments and results.
• Calculation of nuclear radius.

References:

• NCERT Physics Class 12 (Volume I), Chapter 15: Nuclei.

7. Bohr’s Model of the Atom:

• Introduction of quantized energy levels.
• Electron orbits and energy states.
• Limitations of Bohr’s model.

References:

• NCERT Physics Class 12 (Volume I), Chapter 15: Nuclei.

8. Quantum Mechanical Model of the Atom:

• Limitations of Bohr’s model.
• Development of quantum mechanics.
• Wave-particle duality and uncertainty principle.

References:

• NCERT Chemistry Class 12 (Part I), Chapter 2: Structure of the Atom.

9. Quantum Numbers:

• Four quantum numbers (n, l, ml, and ms).
• Significance in describing electron properties.
• Quantum number values and their implications.

References:

• NCERT Chemistry Class 12 (Part I), Chapter 2: Structure of the Atom.

10. Electron Configurations:

• Aufbau principle and Hund’s rule.
• Arrangement of electrons in orbitals.
• Electron configurations of elements.

References:

• NCERT Chemistry Class 12 (Part I), Chapter 2: Structure of the Atom.

11. Periodic Trends:

• Trends in atomic radii.
• Trends in ionization energies.
• Trends in electronegativity.
• Trends in electron affinity.

References:

• NCERT Chemistry Class 11 (Part I), Chapter 3: Classification of Elements and Periodicity in Properties.