What is a _____________________ ?

1. What is a _____________________? • The process by which one or more _____________ change to _____________ one or more different _____________. • In a chemical reaction, the original substances are called the _____________. • The substances that are created are called _____________. • _____________ _____________

2. To be classified as a chemical reaction, a chemical change must occur. • What is the evidence of a chemical reaction? • Change in _____________ • Release of energy as _____________ • Release of energy as _____________ • Production of a _____________ • Reduction or increase of _____________ Absorption or release of _____________ energy

3. Formation of a _____________ _____________ • Formation of a _____________ • Formation of a _____________ – _____________ solid • _____________ change in _____________ • Change in _____________ • You must always verify to ensure that a _____________ change didn’t occur

4. Helping chemical reactions to occur • For a chemical reaction to occur, the reactants must be _____________ _____________. • During chemical reactions, energy is either _____________ (endothermic) or _____________ (exothermic). • As a result, energy can appear as a _____________ (endothermic) or a _____________ (exothermic).

5. Chemical equations also show the physical states and reaction information  heat catalyst Pd

6. With this information, we can now construct chemical equations. • __________________________– a representation of a chemical reaction that uses _____________ to show the relationship between the _____________ and the _____________. • Step one – write a _________________________ • Write the names of _____________ separated by a plus sign . • Use an _____________ to separate the _____________ from the _____________. • Write the names of the _____________ separated by a plus sign

7. Step 2 - Convert the names into _____________. This is known as an _____________ or _____________ equation. • Step 3 - Balance the atoms by changing the _____________ only • This is how we conserve _____________ and obey the law of conservation of _____________

8. Hints when balancing equations 1) Use _____________ to balance atoms involved 2) Balanced equations show _____________ _____________ 3) _____________ change the _____________ when balancing an equation 4) __________________________ can be balanced as a unit