Spotting the difference
Spotting the difference

Chemistry classifies samples by the particles inside them. To decide what a sample is, ask whether all the atoms are the same type, whether different atoms are bonded, or whether different substances are simply together.
Step-by-step lessons on CIE IGCSE Chemistry Elements, compounds and mixtures. Each one builds up to exam-style questions. Build a solid grasp of atomic structure, bonding and the mole concept early, since these underpin almost every other topic, then move on to the more calculation-heavy quantitative and organic chemistry content.