1. Chemical Reactions

2. one or more substances change into different substances these substances have new properties reactants are the substances used up products are the substances produced

3. Chemical Equations there is a set of rules to communicate chemical reactions: word equations – names of chemicals written in full chemical equations – chemical formulas are used to represent chemicals

4. Example: Iron & Sulfur Reactants yields Products Word equation: iron + sulfur  iron (II) sulfide + energy Chemical equation : Fe + S  FeS + energy energy can be either released or absorbed

5. State Symbols found in chemical equations tells the state, or form, of each substance State symbolMeaning (s)solid (l)liquid (g)gaseous (aq)aqueous (dissolved in water)

6. Example: energy + copper (II) carbonate  carbon dioxide + copper (II) oxide energy + CuCO 3 (s)  CO 2 (g) + CuO (s) What would the chemical equation be for: zinc + copper sulfate  zinc sulfate + copper + energy