CHAPTER 8: CHEMICAL EQUATIONS & REACTIONSBy: Jessica Alphonse

CHEMICAL CHANGE

A chemical reaction is a process in which one or more substance turns into a new substance.

Some examples of chemical reactions include wood burning which turns into ash, metal rusting, and baking a cake.

Signs of a chemical reaction include: color change odor given off Substance difficult to reverse. Gas released Solid forming into a liquid.

PHYSICAL CHANGE A physical change is a process in which the

molecules of a substance have not change. Some examples of physical change include water

melting, evaporating or freezing, concrete hardening, and different color paint mixing together.

Signs of a physical change include making a mixture cutting dissolving Grinding Original properties are kept. Change of state.

BALANCING CHEMICAL EQUATIONS Chemical equations show the amount of reactants &

products. For a reaction to take place, molecules and atoms of

the reactants must go together. In order to construct a chemical reaction, you must

first write a word equation. Ex. Methane + Oxygen - Carbon Dioxide. Use the arrow to separate the reactants and the

products. Then turn them into a formula equation. Ex. ?CH4+ O2 - ?CO2 + ?H2O.

TYPES OF REACTIONS

There are many different types of reactions you can easily identify what products are formed.

Decomposition- one substance breaking up into 2 or more substances.

Ex. 2H2O 2H2+O2 Synthesis- A combustion of 2