- Discovery of Electron(Cathode rays)
- Properties of Cathode rays
- More on Properties of Cathode rays
- Discovery of Proton
- Properties of positive rays
- Discovery of Neutron
- Properties of Neutron
- More on Properties of Neutron
- Measurement of e/m Value of Electron
- Measurement of Charge on Electron-Millikan's Drop Method
- More on Measurement of Charge on Electron
- Mass of Electron
- Properties of Fundamenal Particles

- Bohr's Atomic Theory
- Derivation of Radius of Revolving Electron in nth Orbit
- More on Derivation of Radius of Revolving Electron in nth Orbit
- Determining Radius of an Orbit Using Bohr's Equation
- Energy of Revolving Electron
- More on Energy of Revolving Electron
- Energy of Electron in nth Orbit
- Determination of nth Orbit Energy Using Bohr's Equation

- Spectrum
- Continuous Spectrum
- Line Spectrum
- Atomic Emission Spectrum
- Atomic Absorption Spectrum
- Hydrogen Spectrum
- More on Hydrogen Spectrum
- Calculations of Frequency of Photons by Bohr's Theory
- Calculations of Wave Numbers of Photons by Bohr's Theory
- Lyman Series
- Balmer Series
- Paschen Series
- Brackett series
- Pfund series
- Calculation of Wave Number of Spectral series
- Defects of Bohr's Atomic Model
- More on Defects of Bohr's Atomic Model

- Dual Nature of Matter
- More on Dual Nature of Matter
- Experimental Verification of Dual Nature of Matter
- Calculation of De-Broglie's Wavelength

- Heisenberg's Uncertainty Principle
- Concept of Orbital
- Quantum Numbers
- Principal Quantum Numbers (n)
- Azimuthal Quantum Numbers (l)
- Magnetic Quantum Numbers (m)
- Spin Quantum Numbers (s)
- Quantum Numbers of Electrons
- Calculation of Combination of Quantum Numbers
- Shape of s-Orbitals
- Shapes of p-Orbitals
- Shapes of d-Orbitals