Energy Changes

• What happens in exothermic reactions?

  Energy is given out
• What happens in an endothermic reaction?

  Energy is taken in
• If a reversible reaction is exothermic in one direction, then it is endothermic in the other direction
• The changes in energy in a chemical reaction can be shown using an energy level diagram
• What type of reaction occurs breaking a chemical bond that requires energy?

  Endothermic
• What type of reaction occurs when forming a chemical bond that gives out energy?

  Exothermic
• Why do we use fuel cells?

  They are very efficient ways of producing electrical energy, mostly through the use of hydrogen
• What are some advantages of using fuel cells?

  They produce water which is non polluting, are lightweight and are unlikely to break down