Physical Science Notes for Tuesday April 10, 2012 Students need to read Unit B 3.1 pages They should complete the study guide that’s on the back table labeled 7.1 Chemical Reactions Alter the Arrangements of Atoms. (It matched Unit B 3.1) If time permits have students complete the notes on the following slides. Students need to copy the notes on the following slides. They can divide one sheet of paper into 4 sections. Two on the front and two on the back. Or in any arrangement that works.

Chapter Reading You’ll read Unit B Chapter 3.1 pages Complete the study guide labeled 7.1 Chemical Reactions Alter the Arrangements of Atoms. – Remember to write in complete sentences. – Remember to put your name on it and turn it in before you leave. If you finish early you’ll take notes on the following slides.

Chemical Reaction Makes new substances by changing how the atoms are arranged. 2H 2 O  2H 2 + O 2 Signs of a Chemical Reaction 1.Formation of bubbles 2.Change in temperature 3.Change in color 4.Formation of a gas 5.Formation of a solid(precipitate) Synthesis Picture: A + B  AB Na + Cl  NaCl Definition: When 2 or more elements or compounds combine to make a more complex substance Reactants are the substances at the beginning of the reaction. CH 4 + O 2  CO 2 + H 2 O Products are the substances made by the reaction. How to Change Chemical Reaction Rates  Change the surface area  Change temperature  Increase concentration of reactants  Add a catalyst(speeds up) or inhibitor(slows down)

Chemical Reactions Alter the Arrangements of Atoms Unit B Ch. 3.1 (7.1) Chemical Reaction Makes new substances by changing how the atoms are arranged. 2H 2 O  2H 2 + O 2 Signs of a Chemical Reaction 1.Formation of bubbles 2.Change in temperature 3.Change in color 4.Formation of a gas 5.Formation of a solid(precipitate)

Reactants + Products Reactants are the substances at the beginning of the reaction. CH 4 + O 2  CO 2 + H 2 O Products are the substances made by the reaction.

Synthesis Picture: A + B  AB Na + Cl  NaCl Definition: When 2 or more elements or compounds combine to make a more complex substance. Combustion: One reactant is always oxygen. Often also has carbon & hydrogen. Decomposition Definition: When compounds break down into simpler products. AB  A + B 2H 2 O  2H 2 + O 2

How to Change Chemical Reaction Rates  Change the surface area  Change temperature  Increase concentration of reactants  Add a catalyst(speeds up) or inhibitor(slows down)