1. Section 7.2 Chemical Equations 1.To learn to identify the characteristics of a chemical reaction 2.To learn the information given by a chemical equation Objectives

2. Section 7.2 Chemical Equations Chemical reactions involve a rearrangement of the ways atoms are grouped together. A chemical equation represents a chemical reaction. –Reactants are shown to the left of an arrow. –Products are shown to the right of the arrow.

3. Section 7.2 Chemical Equations In a chemical reaction atoms are not created or destroyed. All atoms present in the reactants must be accounted for in the products. –Same number of each type atom on both sides of arrow

4. Section 7.2 Chemical Equations Balancing a Chemical Equation Unbalanced equation Balancing the equation The balanced equation CH 4 + 2O 2  CO 2 + 2H 2 O

5. Section 7.2 Chemical Equations Physical states of compounds are often given in a chemical equation.