Energy Level Diagrams
Energy level diagrams show the energy of reactants and products and the activation energy needed for a reaction to start.
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Energy level diagrams show the energy of reactants and products and the activation energy needed for a reaction to start.
- Products lower than reactants means exothermic
- Activation energy is the peak above reactants
- The difference is the energy change
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Energy Level Diagrams?
Within Chemistry, which covers atoms, bonding, reactions, the periodic table, organic chemistry and the chemistry of everyday life, this topic explains Energy Level Diagrams. Chemistry links what you can see in the lab to the particles and bonds behind it, so each topic here shows that link in a model.
Check that you can explain Energy Level Diagrams in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Energy Level Diagrams helps you explain why substances behave as they do, from cleaning products and food to medicines.
Energy Level Diagrams in detail
An energy level diagram shows the energy of reactants and products and how it changes during a reaction. For an exothermic reaction, the products are lower in energy than the reactants and the difference is the energy released. For an endothermic reaction, the products are higher.
The curve rises from the reactants to a peak, the activation energy, before dropping to the products. A catalyst lowers the peak. Labelling the diagram with the activation energy and overall energy change helps you explain why some reactions need heating to start and why they still release energy.
How the interactive helps you understand Energy Level Diagrams
Watch the energy stores in the interactive. Use any sliders or buttons it offers to change the values and see how the energy stores responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Energy Level Diagrams.
Real-life uses and examples
- Read a chemical equation or diagram and work out what Energy Level Diagrams shows.
- Explain Energy Level Diagrams in an exam by linking the particles involved to what you observe.
- Use Energy Level Diagrams to explain what happens in a lab experiment and why.
Common mistakes to avoid
- Describing what happens without explaining the particles or bonds involved.
- Mixing up the names of substances or ions when you describe Energy Level Diagrams.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Energy Level Diagrams
What is Energy Level Diagrams?
Energy level diagrams show the energy of reactants and products and the activation energy needed for a reaction to start.
What are the most important points about Energy Level Diagrams?
The main points are: Products lower than reactants means exothermic; Activation energy is the peak above reactants; The difference is the energy change.
Why is Energy Level Diagrams useful?
Understanding Energy Level Diagrams helps you explain why substances behave as they do, from cleaning products and food to medicines.
How can I practise Energy Level Diagrams?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Energy Level Diagrams?
Related topics in Chemistry include Chemical Equilibrium, Fuels and Combustion, Alkenes.