GCSE Chemistry (AQA)
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Energy changes
Exothermic and endothermic reactions
Activation Energy
3:00
Reaction Profiles
Spec
4.5.1.2
- Chemical reactions occur when reacting particles collide.
- Particles must collide with sufficient energy for a reaction to occur.
- Without sufficient energy, particles bounce off each other, and no reaction happens.
- The minimum energy needed for a reaction is called activation energy.
- Heating reactants can provide the necessary energy to reach activation energy.
- Reactions vary in activation energy; some occur at room temperature, others require additional energy.
- All reactions, including exothermic ones, have an activation energy.
- Exothermic reactions release energy to the surroundings but still require initial activation energy.
- A bunsen burner is an example where initial energy is needed to start a reaction, which then releases more energy.
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