Grade 12 Chemistry – Unit 1: Structure and
Properties of Matter
Comprehensive Notes (Clean • Organized • Student-Friendly)
Table of Contents
1. Introduction to Structure & Properties
2. Atomic Structure Review
3. Quantum Mechanical Model
4. Electron Configuration & Orbital Diagrams
5. Periodic Trends
6. Chemical Bonding Overview
7. Lewis Structures & VSEPR Theory
8. Molecular Polarity
9. Intermolecular Forces
10. Properties of Substances
11. Practice Problems
1. Introduction to Structure & Properties of Matter
Chemistry examines how the structure of atoms and molecules affects their physical and chemical
properties. Understanding the microscopic level allows us to explain macroscopic behaviours such as
boiling point, reactivity, solubility, and conductivity.
Key Questions:
• Why do some molecules dissolve in water while others don't?
• Why do metals conduct electricity but molecular compounds don’t?
• Why do ionic compounds have high melting points?
2. Atomic Structure Review
2.1 Subatomic Particles
Particle Charge Mass (relative) Location
Proton +1 1 amu Nucleus
1
, Particle Charge Mass (relative) Location
Neutron 0 1 amu Nucleus
Electron –1 \~0 amu Orbitals
2.2 Bohr Model (Review)
• Electrons orbit the nucleus in energy levels (shells).
• Electrons have quantized energy.
Diagram:
(Bohr Model - Simplified)
2e- 8e-
-------- -----------
| O | | |
| | | |
-------- -----------
3. Quantum Mechanical Model
The Bohr model was replaced by the quantum mechanical model, which describes electrons as
probability clouds rather than fixed orbits.
3.1 Orbitals
Orbitals represent regions of space where electrons are likely to be found.
Types of orbitals:
• s-orbital: spherical (holds 2 e⁻)
• p-orbital: dumbbell-shaped (holds 6 e⁻ total)
• d-orbital: complex shapes (holds 10 e⁻)
Diagram:
s orbital: p orbital:
___ ___ ___ ___
/ \ ( x ) ( y ) ( z )
\___/ \___/ \___/ \___/
2
Properties of Matter
Comprehensive Notes (Clean • Organized • Student-Friendly)
Table of Contents
1. Introduction to Structure & Properties
2. Atomic Structure Review
3. Quantum Mechanical Model
4. Electron Configuration & Orbital Diagrams
5. Periodic Trends
6. Chemical Bonding Overview
7. Lewis Structures & VSEPR Theory
8. Molecular Polarity
9. Intermolecular Forces
10. Properties of Substances
11. Practice Problems
1. Introduction to Structure & Properties of Matter
Chemistry examines how the structure of atoms and molecules affects their physical and chemical
properties. Understanding the microscopic level allows us to explain macroscopic behaviours such as
boiling point, reactivity, solubility, and conductivity.
Key Questions:
• Why do some molecules dissolve in water while others don't?
• Why do metals conduct electricity but molecular compounds don’t?
• Why do ionic compounds have high melting points?
2. Atomic Structure Review
2.1 Subatomic Particles
Particle Charge Mass (relative) Location
Proton +1 1 amu Nucleus
1
, Particle Charge Mass (relative) Location
Neutron 0 1 amu Nucleus
Electron –1 \~0 amu Orbitals
2.2 Bohr Model (Review)
• Electrons orbit the nucleus in energy levels (shells).
• Electrons have quantized energy.
Diagram:
(Bohr Model - Simplified)
2e- 8e-
-------- -----------
| O | | |
| | | |
-------- -----------
3. Quantum Mechanical Model
The Bohr model was replaced by the quantum mechanical model, which describes electrons as
probability clouds rather than fixed orbits.
3.1 Orbitals
Orbitals represent regions of space where electrons are likely to be found.
Types of orbitals:
• s-orbital: spherical (holds 2 e⁻)
• p-orbital: dumbbell-shaped (holds 6 e⁻ total)
• d-orbital: complex shapes (holds 10 e⁻)
Diagram:
s orbital: p orbital:
___ ___ ___ ___
/ \ ( x ) ( y ) ( z )
\___/ \___/ \___/ \___/
2
