Key term
AQA GCSE Combined Science Chemistry 8464
Atomic Structure and the Periodic Table
Topic overviewAtoms, elements and compoundsWord equations, symbols and balanced equationsMixturesFrom the plum pudding model to the nuclear modelBohr, Chadwick and the modern model of the atomRelative electrical charges of subatomic particlesSize and mass of atomsRelative atomic mass and electronic structureThe periodic tableDevelopment of the periodic tableMetals and non-metalsGroup 0Group 1Group 7
Bonding, Structure, and the Properties of Matter
Topic overviewChemical bonds, including metallic bondingIonic bondingIonic compoundsCovalent bonding and how it is representedThe three states of matter and changes of statePredicting state, state symbols, and the limits of the particle modelProperties of ionic compoundsProperties of small moleculesPolymers and giant covalent structuresProperties of metals and alloys, and why metals conductDiamond and graphiteGraphene and fullerenes
Chemical Analysis
Chemical Changes
Topic overviewThe reactivity seriesMetal oxides, extraction, and redox in terms of electronsAcids reacting with metals, neutralisation and saltsSoluble saltsThe pH scale and neutralisationThe process of electrolysis, and molten ionic compoundsUsing electrolysis to extract metalsElectrolysis of aqueous solutions
Chemistry of the Atmosphere
Topic overviewThe Earth's early atmosphereHow oxygen increased and carbon dioxide decreasedThe gases in today's atmosphere, and which are greenhouse gasesHuman activities which contribute to an increase in greenhouse gases in the atmosphereGlobal climate change and carbon footprintsAtmospheric pollutants from fuels, and their effects
Energy Changes
Organic Chemistry
Quantitative Chemistry
The Rate and Extent of Chemical Change
Energy Changes
Reaction profiles
- 3 things to know
- Chemistry Paper 1
Overview
The two conditions for colliding particles to react, activation energy and why not every collision leads to a reaction, what a reaction profile shows, reading the overall energy change and activation energy from it, and the profiles of exothermic and endothermic reactions.
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
State the two conditions that must be met before colliding particles will react.
Key term
Explain why not every collision between reactant particles leads to a reaction.
Questions from this subtopic
Each one with the model answer underneath.
- 1
State the two conditions that must be met before colliding particles will react.
Model answer
The particles must actually collide with each other, and the collision must have enough energy.
- 2
Define activation energy.
Model answer
It is the minimum amount of energy that particles must have in order to react.
- 3
Explain why not every collision between reactant particles leads to a reaction.
Model answer
Only collisions carrying at least the activation energy have enough energy to start breaking the existing bonds, so less energetic collisions have no effect.
- 4
A reaction has a very high activation energy. Suggest what this means about the reaction at room temperature.
Model answer
Very few particles have that much energy, so the reaction is extremely slow or appears not to happen at all.
- 5
What is meant by saying that particles must collide with sufficient energy?
Model answer
The colliding particles must between them have at least the activation energy of the reaction.
- 6
What three things can a reaction profile show about a reaction?
Model answer
The relative energies of the reactants and products, the activation energy, and the overall energy change.
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