12/8 - 8 th Grade Agenda Learning Objective: Learn about Fire Safety Collect HW: Reading & Notetaking: p.117 – 118 Textbook Reading p HW: Reading & Notetaking p.119 – 122 Reminder HW: Science Fair Background due 1/14 & 1/15 (10 Points)

Daily Reflection Prompt: What is the difference between an exothermic and endothermic reaction?

What is Conservation of Mass? The total mass of the reactant must equal the total mass of the products During a chemical reaction, matter is not created or destroyed

Open End vs Closed End systems

What is a coefficient 2 H 2 + O 2  2 H 2 O The number in front of a chemical formula in a chemical is called an coefficient It tells you how many molecules or atoms of each reactant or product take part in the reaction

What is a Chemical Equation Reactant + Reactant  Product + Product H 2 + O 2  H 2 O 2 Subscript shows the number of atoms of an element in a molecule

Balancing Equation

Types of Chemical Reactions What is a Synthesis? When two or more substances (elements or compounds) combine to make a more complex substance, the process is called a synthesis

Types of Chemical Reactions What is Decomposition? Decomposition reaction breaks down compounds into simpler products

What is a Replacement reaction? It is similar to a girl switching boyfriends A reaction in which one element replaces another in a compound

What is an activation energy? The minimum amount of energy that has to be added to start a reaction. Think of a chemical reaction as being like a rock resting behind a ridge at the top of a hill.

Energy in Chemical Reactions Every chemical reaction involves a change of energy. (In the test)

What affects the rate of chemical reactions? Concentration Surface Area Temperature Catalysts

What is a Catalyst? A Material that increases the rate of a chemical reaction by lowering the activation energy What does it mean?

Catalyst Demonstration Paper clips represents reactants If I place two paper clips in a cup, no matter how hard I shake the cup, I can not get the paper clips to link up.

Catalyst Demonstration In this model, Paper clip = Reactant Dollar bill = Catalyst

Another Catalyst Demonstration Hydrogen Peroxide decomposes into Water and Oxygen slowly 2H 2 O 2 -> 2H 2 O + O 2 Yeast acts as a Catalyst and speeds up the reaction.

What is an enzyme or catalyst? Enzyme is biological catalyst which provide a surface on which reactions take place. This helps reactions happen at lower temperatures because it lowers activation energy.

What is combustion? Combustion is a rapid reaction between oxygen and a substance called a fuel.

What are the three things necessary to start and maintain a fire? Fuel Oxygen Heat

What are four common sources of fires at home? Small heaters Fires in the kitchen Faulty electric wiring Carelessness with cigarettes.

How can you fight a fire? A. Blow air on it? B. Cover it with baking soda? C. Use a fire extinguisher? D. Pour water on it?

Which of the following is a safety aid in a fire safe home. A) smoke detectors B) gasoline can in the basement C) Fire extinguishers D) Box of baking soda in the kitchen