Unit 2979: Atomic Structure, Periodicity, and Chemical Bonding

1. Historical Development of Atomic Theory

1.1 Early Atomic Models

• Dalton’s Atomic Theory: indivisible atoms and elements
• Thomson’s Plum Pudding Model: discovery of the electron

1.2 Nuclear Model of the Atom

• Rutherford’s Gold Foil Experiment: nucleus discovery
• Bohr’s Model: quantized electron orbits

1.3 Evolution of Atomic Theory

• Transition from classical to quantum models
• Impact of discoveries on modern atomic theory

2. Structure of the Atom

2.1 Subatomic Particles

• Protons, neutrons, electrons: properties and charges

2.2 Atomic Number and Mass Number

• Definition and significance
• Relationship to elements and isotopes

2.3 Isotopes

• Concept and examples
• Applications and implications

3. Electron Configuration

3.1 Energy Levels and Sublevels

• Principal energy levels (shells)
• Sublevels (s, p, d, f) and their capacities

3.2 Aufbau Principle

• Order of orbital filling
• Pauli Exclusion Principle and Hund’s Rule

3.3 Writing Electron Configurations

• Using the periodic table to determine configurations
• Examples for selected elements

4. Periodic Table and Periodic Trends

4.1 Organization of the Periodic Table

• Periods and groups
• Metals, nonmetals, metalloids

4.2 Atomic Size (Atomic Radius)

• Trends across periods and groups
• Factors influencing atomic size

4.3 Ionization Energy

• Definition and trend patterns
• Successive ionization energies

4.4 Electron Affinity

• Definition and general trends
• Exceptions and anomalies

4.5 Electronegativity

• Concept and measurement (Pauling scale)
• Relationship to bonding and reactivity

5. Chemical Bonding

5.1 Types of Chemical Bonds

• Ionic bonds: formation and properties
• Covalent bonds: polar and nonpolar
• Metallic bonds: characteristics and electron sea model

5.2 Relationship Between Bonding and Element Properties

• Melting/boiling points, conductivity, solubility
• Bond strength and stability

6. Molecular Geometry and VSEPR Theory

6.1 Valence Shell Electron Pair Repulsion (VSEPR) Theory

• Basic principles
• Predicting molecular shapes

6.2 Types of Molecular Geometries

• Linear, bent, trigonal planar, tetrahedral, trigonal bipyramidal, octahedral

6.3 Effect of Lone Pairs

• Lone pairs vs bonding pairs on shape
• Examples of molecules and ions

7. Periodic Trends and Chemical Reactivity

7.1 Influence of Electronegativity and Ionization Energy

• Reactivity of metals and nonmetals
• Formation of ionic and covalent compounds

7.2 Reactivity Patterns

• Alkali metals, halogens, transition metals
• Factors affecting reactivity

8. Nuclear Chemistry

8.1 Radioactivity and Nuclear Reactions

• Types of radiation: alpha, beta, gamma
• Nuclear decay processes: alpha decay, beta decay, gamma emission

8.2 Isotopes in Nuclear Chemistry

• Stability and radioactive isotopes

8.3 Applications of Nuclear Chemistry

• Medicine: diagnostic imaging, radiotherapy
• Industry: radiotracers, sterilization
• Energy production: nuclear fission and fusion