Element, compounds and mixtures
- All substances can be classified into one of these three types
- Elements
- Compounds
- Mixtures
What is an element?
- A substance made of atoms that all contain the same number of protons and cannot be split into anything simpler
- There are 118 elements found in the Periodic Table
- E.g. copper, iron, magnesium
What is a compound?
- A pure substance made up of two or more elements chemically combined
- There is an unlimited number of compounds
- Compounds cannot be separated into their elements by physical means
- E.g. copper(II) sulfate (CuSO4), calcium carbonate (CaCO3), carbon dioxide (CO2)
What is a mixture?
- A combination of two or more substances (elements and/or compounds) that are not chemically combined
- Mixtures can be separated by physical methods such as filtration or evaporation
- E.g. sand and water, oil and water, sulfur powder and iron filings
Particle diagram showing elements, compounds and mixtures
All substances can be classified as an element, compound or mixture
Examiner Tip
As well as learning the definitions for an element, compound and mixture, you must be able to classify any given substance.
