Bond Energies

• • Bond breaking is endothermic - energy needs to be supplied to break existing bonds
  • Bond forming is exothermic - energy is released when new bonds form
• • In exothermic reactions, energy released from forming bonds is greater than energy used to break them
  • In endothermic reactions, energy used to break bonds is greater than energy released from forming bonds
• overall energy change = energy required to break bonds - energy released by forming bonds