Chemistry Ordinary Level

Introduction to Matter

Matter is defined as anything that has mass and occupies space. Everything around us—air, water, soil, living organisms, and even the stars—is made up of matter. Matter exists in various forms and can undergo physical and chemical changes.

States of Matter

Solid: Has a fixed shape and volume. Particles are tightly packed and vibrate in place. Examples: ice, wood, metal.
Liquid: Has a fixed volume but no fixed shape. Particles are loosely packed and can flow. Examples: water, oil, milk.
Gas: Has no fixed shape or volume. Particles are far apart and move freely. Examples: oxygen, carbon dioxide.
Plasma: A high-energy state where atoms are ionized. Found in stars and lightning.

Key Definitions

Atom: The smallest unit of an element that retains its chemical properties.

Element: A pure substance made of only one type of atom. Example: Hydrogen (H), Oxygen (O).

Compound: A substance formed when two or more elements chemically combine. Example: Water (H₂O).

Mixture: A combination of two or more substances that are not chemically bonded. Example: Sand and salt.

Types of Mixtures

Homogeneous Mixture: Uniform composition throughout. Example: Sugar dissolved in water.
Heterogeneous Mixture: Non-uniform composition. Example: Mixture of sand and iron filings.

Transition States of Matter

Initial State	Final State	Process Name	Description
Solid	Liquid	Melting	Heat causes particles to loosen and flow.
Liquid	Solid	Freezing	Cooling causes particles to lock into place.
Liquid	Gas	Evaporation	Particles gain energy and escape into air.
Gas	Liquid	Condensation	Particles lose energy and come closer together.
Solid	Gas	Sublimation	Solid turns directly into gas without becoming liquid.
Gas	Solid	Deposition	Gas turns directly into solid without becoming liquid.

Separation Techniques for Mixtures

Hand Picking: Used to separate large visible particles manually. Example: Removing stones from rice.
Paper Chromatography: Used to separate colored substances. Example: Separating ink pigments.
Separating Funnel: Used to separate immiscible liquids. Example: Oil and water.
Simple Distillation: Used to separate a solvent from a solution. Example: Purifying water from salt water.
Fractional Distillation: Used to separate a mixture of liquids with different boiling points. Example: Separating components of crude oil.