9th Class Chemistry — Full Book Notes
Punjab Board / PCTB-PECTAA • Session 2026–27 • Original revision notes
How to use: These notes are a concise revision guide covering the 13 current chapters. For exact textbook
wording, diagrams and complete exercises, keep your prescribed textbook alongside these notes.
Contents
Chap Topic
ter
1 States of Matter and Phase Changes
2 Atomic Structure
3 Chemical Bonding
4 Stoichiometry
5 Energetics
6 Equilibria
7 Acid Base Chemistry
8 Periodic Table and Periodicity
9 Group Properties and Elements
10 Environmental Chemistry
11 Hydrocarbons
12 Empirical Data Collection and Analysis
13 Laboratory and Practical Skills
, 1. States of Matter and Phase Changes
Core ideas
• Matter is anything that has mass and occupies space. Its particles are continuously moving.
• Solid: fixed shape and volume; particles are closely packed. Liquid: fixed volume but no fixed shape. Gas:
neither fixed shape nor fixed volume.
• Plasma is an ionized state of matter containing charged particles.
Phase changes
• Melting: solid → liquid. Freezing: liquid → solid. Vaporization: liquid → gas. Condensation: gas → liquid.
• Sublimation: solid → gas directly. Deposition: gas → solid directly.
• During a phase change, energy is absorbed or released while temperature may remain constant at the
transition point.
Key terms
• Kinetic molecular theory explains matter in terms of moving particles and their kinetic energy.
• Diffusion is the spreading of particles from higher concentration to lower concentration.
Exam formulas / facts
• Kelvin temperature: K = °C + 273.15.
• Heating generally increases particle kinetic energy; cooling generally decreases it.
Punjab Board / PCTB-PECTAA • Session 2026–27 • Original revision notes
How to use: These notes are a concise revision guide covering the 13 current chapters. For exact textbook
wording, diagrams and complete exercises, keep your prescribed textbook alongside these notes.
Contents
Chap Topic
ter
1 States of Matter and Phase Changes
2 Atomic Structure
3 Chemical Bonding
4 Stoichiometry
5 Energetics
6 Equilibria
7 Acid Base Chemistry
8 Periodic Table and Periodicity
9 Group Properties and Elements
10 Environmental Chemistry
11 Hydrocarbons
12 Empirical Data Collection and Analysis
13 Laboratory and Practical Skills
, 1. States of Matter and Phase Changes
Core ideas
• Matter is anything that has mass and occupies space. Its particles are continuously moving.
• Solid: fixed shape and volume; particles are closely packed. Liquid: fixed volume but no fixed shape. Gas:
neither fixed shape nor fixed volume.
• Plasma is an ionized state of matter containing charged particles.
Phase changes
• Melting: solid → liquid. Freezing: liquid → solid. Vaporization: liquid → gas. Condensation: gas → liquid.
• Sublimation: solid → gas directly. Deposition: gas → solid directly.
• During a phase change, energy is absorbed or released while temperature may remain constant at the
transition point.
Key terms
• Kinetic molecular theory explains matter in terms of moving particles and their kinetic energy.
• Diffusion is the spreading of particles from higher concentration to lower concentration.
Exam formulas / facts
• Kelvin temperature: K = °C + 273.15.
• Heating generally increases particle kinetic energy; cooling generally decreases it.
