Chapter - 2.1
Pages Covered - 47 - 50
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
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
Good