Detailed Notes: Structure of Atom -B

1. Quantum Numbers:

• Principal Quantum Number (n) denotes the main energy level of an electron. (Ref: NCERT Class 11, Chap 2)
• Azimuthal Quantum Number (l) represents the shape of the electron orbital. (Ref: NCERT Class 11, Chap 2)
• Magnetic Quantum Number (ml) describes the orientation of the orbital in space. (Ref: NCERT Class 11, Chap 2)
• Spin Quantum Number (ms) indicates the intrinsic spin of the electron. (Ref: NCERT Class 11, Chap 2)

2. Electronic Configurations:

• Aufbau Principle: Electrons fill orbitals in order of increasing energy levels. (Ref: NCERT Class 11, Chap 2)
• Pauli Exclusion Principle: No two electrons can have the same set of four quantum numbers. (Ref: NCERT Class 11, Chap 2)
• Hund’s Rule: Electrons in the same orbital have the same spin. (Ref: NCERT Class 11, Chap 2)

3. Electron Energy Levels:

• Energy Level Diagrams: Represent the arrangement of electrons in an atom based on their energy levels. (Ref: NCERT Class 11, Chap 2)
• Orbitals: Three-dimensional regions where the probability of finding an electron is maximum. (Ref: NCERT Class 11, Chap 2)
• s, p, d, and f Orbitals: Different types of orbitals with characteristic shapes. (Ref: NCERT Class 11, Chap 2)

4. Periodic Properties:

• Atomic Radii: Trends in atomic radii across periods and groups. (Ref: NCERT Class 11, Chap 3)
• Ionization Energy: Energy required to remove an electron from an atom. (Ref: NCERT Class 11, Chap 3)
• Electronegativity: Ability of an atom to attract electrons. (Ref: NCERT Class 11, Chap 3)
• Periodic Trends: Patterns in properties of elements based on their position in the periodic table. (Ref: NCERT Class 11, Chap 3)

5. Quantum States and Atomic Spectroscopy:

• Quantum States: Specific energy levels occupied by electrons in atoms. (Ref: NCERT Class 12, Chap 1)
• Atomic Spectra: Emission and absorption of light by atoms when electrons transition between energy levels. (Ref: NCERT Class 12, Chap 1)
• Spectroscopic Notation: Describing atomic spectra using spectroscopic terms. (Ref: NCERT Class 12, Chap 1)

6. Quantum Mechanics and Wave-Particle Duality:

• Wave-Particle Duality: Electrons exhibit both particle and wave-like properties. (Ref: NCERT Class 12, Chap 1)
• Quantum Mechanical Model: Describes the behavior of electrons in terms of probability waves. (Ref: NCERT Class 12, Chap 1)
• Schrodinger Equation: Mathematical equation describing the wave function of an electron. (Ref: NCERT Class 12, Chap 1)

7. Effective Nuclear Charge:

• Effective Nuclear Charge (Z-eff): Net positive charge experienced by an electron in an atom. (Ref: NCERT Class 12, Chap 2)
• Shielding Effect: Reduction in Z-eff due to the presence of other electrons. (Ref: NCERT Class 12, Chap 2)
• Slater’s Rules: Approximating Z-eff for multi-electron atoms. (Ref: NCERT Class 12, Chap 2)

8. Hund’s Rule and Multiple Electron Systems:

• Hund’s Rule: Electron configurations with maximum spin multiplicity are more stable. (Ref: NCERT Class 12, Chap 2)
• Exchange Energy: Energy stabilization due to exchange interactions between electrons. (Ref: NCERT Class 12, Chap 2)
• Stability of Multiple Electron Systems: Explaining the stability of atomic configurations. (Ref: NCERT Class 12, Chap 2)

9. Atomic Radii and Ionization Energies:

• Atomic Radii: Trends in atomic radii across periods and groups. (Ref: NCERT Class 12, Chap 2)
• Ionization Energy: Energy required to remove an electron from an atom. (Ref: NCERT Class 12, Chap 2)
• Factors Affecting Ionization Energy: Effective nuclear charge, number of valence electrons. (Ref: NCERT Class 12, Chap 2)

10. Exceptions and Irregularities in Electronic Configurations:

• Exceptions to General Rules: Deviations from expected electronic configurations. (Ref: NCERT Class 12, Chap 2)
• Half-filled or Fully Filled Orbitals: Stability of certain configurations. (Ref: NCERT Class 12, Chap 2)
• Irregularities in Transition Metals: Causes and consequences. (Ref: NCERT Class 12, Chap 3)