2) Reaction Profiles

• In chemical reactions, atoms are rearranged as old bonds are broken and new bands are formed.
• The minimum amount of energy that the particles must have for a reaction to take place is called the activation energy.
• The energy changes in a chemical reaction can be shown using an energy level diagram or reaction profile.
• In an exothermic reaction:

  • energy is given out to the surroundings
  • the products have less energy than the reactants.
• In an endothermic reaction:

  • energy is being taken in from the surroundings
  • the products have more energy than the reactants.
• Catalysts reduce the activation energy needed for a reaction. This makes the reaction go faster.