Overview
This lecture covers the physical and chemical properties of matter, how to identify them, and key examples relevant for students.
Classification of Matter
- Matter can be classified as pure substances or mixtures.
- Pure substances include elements (metals, metalloids, non-metals) and compounds (organic, inorganic).
- Mixtures can be solutions, colloids, or suspensions.
Physical Properties of Matter
- Physical properties can be observed without changing the material’s identity (e.g., size, color, texture, state, volume).
- Examples: Magnetism in iron nails, malleability in gold (can be shaped into sheets or jewelry).
- Physical property changes do not form new substances.
Chemical Properties of Matter
- Chemical properties can only be observed when substances produce one or more new substances.
- Combustion: Rapid reaction of fuel with oxygen, producing heat, light, and new substances (e.g., burning paper forms smoke and ash).
- Electrolysis: Use of electricity to break down compounds into elements (e.g., water splitting into hydrogen and oxygen).
- Oxidation: Interaction with oxygen to form new products (e.g., rust formation on metals, bananas turning black).
- Tarnishing: Slow reaction of metals with substances like oxygen or sulfur, producing a dark coating and loss of shine.
Quiz Review (Examples)
- Gold shaped into jewelry shows a physical property (malleability).
- Jewelry losing shine is due to tarnishing (chemical property).
- Burning wood releasing smoke is a result of combustion.
- Bananas turning black is caused by oxidation.
- Water separating into hydrogen and oxygen is due to electrolysis.
Key Terms & Definitions
- Physical Property — Characteristic observed without changing the substance's identity.
- Chemical Property — Characteristic observed when a new substance is produced.
- Combustion — Rapid reaction with oxygen, releasing energy and forming new substances.
- Electrolysis — Process using electricity to break a compound into simpler substances.
- Oxidation — Reaction with oxygen forming a new product.
- Tarnishing — Slow formation of a dark coating on metals due to reaction with substances in the environment.
- Malleability — Ability of a material to be shaped or formed without breaking.
Action Items / Next Steps
- Review the classification and examples of physical and chemical properties.
- Practice identifying properties in daily life and complete any assigned quiz or exercises.