1. Chemical Reactions, Formulas, and Equations

2. Chemical Formulas Chemical formula - A shorthand notation for a compound or diatomic element. Shows the elements and how many atoms of each element are in the compound/molecule. C 6 H 12 O 6 Element Symbols Subscripts Subscripts – Number written below and to the right of a chemical symbol. Shows the number of atoms of each element.

3. Signs of a Chemical Reaction Clues to chemical reaction 1. Gas Formation 2. Precipitate 3. Color Change 4. Energy Change 5. Sound 6. Light 7. Odor

4. Chemical Reactions Chemical reaction – a process by which one or more substances undergo a chemical change (React) to produce one or more different (New) substances. New substances form because chemical bonds break and form new bonds. Different _________ and ________ properties Chemical Reactions are shown by writing chemical equations. PhysicalChemical

5. Chemical Equations and Parts Chemical Equation – A representation of a chemical reaction where the reactants and products are expressed in formulas Reactants - Starting materials that change Products – New substances formed “Ending Materials” _______________ produce the _________________. Coefficients – Number placed in front of a formula to balance equations. REACTANTS 2H 2 + O 2 2H 2 O PRODUCTS Yields ReactantsProducts Coefficients