AQA GCSE Chemistry · 8462
Specification 4.2.1.4, 4.7.2.1 · Paper 1, Paper 2
A formula that shows the actual number of atoms of each element in one molecule.
Revise: Covalent Bonding MechanismTo deduce a molecular formula from a model, identify one complete molecule, count the atoms of each element and write those actual counts as subscripts. For example, a model containing two carbon atoms bonded to six hydrogen atoms represents C₂H₆—not CH₃, which gives only the simplest ratio.
- Revise: Alkene Structure
A formula showing the numbers of each type of atom in a molecule, but not how they are bonded.