5.1 Guided ReadingName:

“ The Nature of Chemical Reactions”

1) A chemical reaction occurs when a new is produced. When baking bread yeast and sugar react to form dioxide and acid.

2) The release of is one sign of a chemical reaction. A chemical change also occurs almost any time there is a change.

3) When gasoline is burned in an engine isooctane and oxygen react to produce and .

4) The are the substances that undergo a chemical change and the is the result of the change.

5) In the reaction new product atoms are not and old reactant atoms are not . Instead the atoms are and new bonds are formed.

6) The Isooctane-oxygen reaction needs to get started. In the case of a car engine a small starts the reaction. For the atoms to react the old bonds must be .

7) The energy to break bonds can come from heat , , , or . As long as molecules enough energy is transferred to break bonds.

8) Each carbon dioxide molecule has oxygen atoms connected to one atom with a bond. The water is made up two atoms forming a single bond with one atom.

9) When new bonds form is released. When gas burns energy is releases in the form of and .

10) energy is stored within atoms and molecules and can be when a substance reacts.

11) The total energy the reaction is to the total energy of the products and their surroundings.

12) In an reaction energy is transferred to the surroundings as . This causes the temperature to rise.

13) An reaction more energy is needed to break the bonds in the reaction than is given off bonds in the products. This lowers the temperature.

14) is an endothermic reaction where plants use energy from to convert carbon dioxide and to and oxygen.