Summary
Elements, compounds, and mixtures are fundamental concepts in chemistry that describe how substances are composed and interact.
- Element — Substance made from only one type of atom
Example: Carbon (C) - Compound — Substance made from two or more elements that undergoes chemical reaction with each other
Example: Bauxite is a compound made of Aluminium - Mixture — Substances made by mixing two or more elements or compounds (no chemical reaction)
Example: Sea water is a mixture of salt, water, and other dissolved substances
Exam Tips
Key Definitions to Remember
- An element is a substance made from only one type of atom.
- A compound is a substance made from two or more elements that undergo a chemical reaction.
- A mixture is made by mixing two or more substances without a chemical reaction.
Common Confusions
- Not all molecules are compounds; some are made of the same element.
- Mixtures do not involve chemical reactions, unlike compounds.
Typical Exam Questions
- What is an element?
A substance made from only one type of atom. - How is a compound different from a mixture?
Compounds involve chemical reactions between elements, mixtures do not. - Identify if air is an element, compound, or mixture.
Air is a mixture.
What Examiners Usually Test
- Ability to distinguish between elements, compounds, and mixtures.
- Understanding of examples of each type of substance.