Bond Breaking and Bond Forming

Calculate energy changes in a chemical reaction by considering bond-making and bond-breaking energies.
Understand that energy must be supplied to break bonds in reactants, and energy is released when new bonds are formed in products.
Calculate the overall energy change of a reaction as the difference between the sum of energy needed to break bonds and the sum of energy released when forming bonds.
Explain that in an exothermic reaction, the energy released from forming new bonds is greater than the energy required to break existing ones.
Explain that in an endothermic reaction, the energy required to break existing bonds is greater than the energy released from forming new bonds.
Calculate the energy transferred in chemical reactions between simple molecules in the gas state using supplied bond energies.

What you need to know