Lecture Notes on Atomic Structure and Quantum Mechanics

Overview

• Discussion on the complete chapter of Atomic Structure, including advanced levels.
• Explanation of various scientific theories and models related to atomic structure.

Key Concepts

Introduction to Atomic Structure

• Atomic Structure often referred to as "Structure of Atom" in various textbooks.
• Emphasis on interactive learning and problem-solving throughout the session.
• Background of the lecturer: Sakshi Vora, IIT Roorkee graduate with over 8 years of teaching experience.

Dalton's Atomic Theory

• Matter is composed of small particles called atoms.
• Atoms cannot be created or destroyed in chemical reactions.
• Each element has unique atomic properties.

Thomson's Atomic Model

• Proposed the "Plum Pudding Model".
• Atoms are spherical with positive charge distributed uniformly, and electrons embedded within.

Rutherford's Atomic Model

• Discovery of the nucleus as a central core of the atom.
• Majority of an atom's mass is concentrated in the nucleus.
• Electrons move in orbits around the nucleus, influenced by electrostatic forces.

Bohr's Model of the Atom

• Electrons exist in defined energy levels or shells.
• Each shell has a specific energy associated with it.
• Electrons can move between these levels by absorbing or emitting energy (photons).

Quantum Theory and Electronic Configuration

• Introduction to quantum numbers: principal (n), azimuthal (l), magnetic (m), and spin (s).
• Explanation of allowed values for quantum numbers.
• Electronic configurations indicate how electrons are distributed in atomic orbitals.

Heisenberg's Uncertainty Principle

• It is impossible to know simultaneously the exact position and momentum of a particle.
• Formulation of the principle: Δx · Δp ≥ ħ/4π, where ħ is the reduced Planck's constant.

Schrödinger's Wave Equation

• Relationship between the wave behavior of particles and their energy states.
• Wave functions (ψ) represent the probability amplitude of a particle's position.
• The square of a wave function (ψ^2) gives the probability density of finding a particle in a given space.

Important Graphs in Quantum Mechanics

• Graphs representing probability densities and radial distribution functions are key to understanding electronic configurations.
• Understanding the shapes and orientations of orbitals (s, p, d, f) is important.

Summary of Key Formulas

• Energy of an electron in an orbital: E = -13.6 eV/n² (for hydrogen)
• Radius of orbit: r = 0.529 n² (in Angstroms)
• Velocity of an electron: v = 2.18 × 10⁶ m/s (for the first orbit)
• Wave function relationships:
  • λ = h/p
  • λ = h/√(2mK.E.)

Conclusion

• The lecture covered various aspects of atomic structure, including historical theories and modern quantum mechanics.
• Future learning will focus on electronic configurations and further applications of quantum theories.