- All alkenes contain a double carbon bond, which is shown as two lines between two of the carbon atoms i.e. C=C.
- All alkenes contain a double carbon bond, which is the alkene functional group and is what allows alkenes to react in ways that alkanes cannot.
- The names and structure of the first four alkenes are shown below.
Table showing the formulae and structures of the first four alkanes
- Compounds that have a C=C double bond are also called unsaturated compounds.
- That means they can make more bonds with other atoms by opening up the C=C bond and allowing incoming atoms to form another single bond with each carbon atom of the functional group.
- Each of these carbon atoms now forms 4 single bonds instead of 1 double and 2 single bonds.
- This makes them much more reactive than alkanes.
A carbon carbon double can break and form a single bond, allowing more atoms to attach to the carbon atoms
AQA GCSE Chemistry Notes
Want to aim for a Level 9?
See if you’ve got what it takes. Test yourself with our topic questions.
More AQA GCSE (9-1) Chemistry Revision Resources
Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.