1. FEB. 10-11 DO NOW: QUIET FOR 5! Objective: SWBAT… - explain the ways chemicals can react in terms of particles (atoms and molecules) HW: 1.Law of Conservation of Mass Post-lab (due next week) 2.Balancing Equations HW Question: What were chemical changes again? What are some examples of chemical change?

2. Interactive Notes As a class: 1. What did you observe in the lab when examining amounts of chemicals? 2. When the baking soda reacts with vinegar, what happens to them? Do they disappear? Where could they possibly go?

3. Interactive Notes – Conservation of Mass Ideally: - Closed system NOT open to environment; whatever is in the system, stays in the system - Open system open to environment; chemicals can leave the system

4. Interactive Notes – Conservation of Mass Answer in notebook with your group (1 minute): You learned in physics the Law of Conservation of Energy. What did this law state?

5. Interactive Notes – Conservation of Mass Answer in notebook with your group (1 minute): Use your previous answer to help with this question: What do you think the Law of Conservation of Mass states?

6. Interactive Notes – Conservation of Mass SUPER IMPORTANT! SUPER IMPORTANT! SUPER IMPORTANT Mass (or matter) cannot be created nor destroyed

7. Interactive Notes – Conservation of Mass Draw the following picture: Explain in your notebook what is happening here (2 minute)

8. Interactive Notes – Conservation of Mass For the following picture: “Two connected triangles are added with two connected squares and become one connected triangle and square.”

9. Interactive Notes – Conservation of Mass For the following picture: “Two connected triangles are added with two connected squares and become one connected triangle and square.” What do you notice could be wrong with that statement? Talk with group and answer in notebook (2 min., signature)

10. Interactive Notes – Conservation of Mass For the following picture: All shapes are accounted for now!

11. Interactive Notes – Conservation of Mass -A chemical reaction is when chemical substances rearrange atoms to form entirely new substances. -Chemical reactions are represented with equations. These equations can be translated into sentences -i.e. Hydrogen gas reacts with oxygen gas to form water vapor.

12. Interactive Notes – Conservation of Mass Hydrogen gas reacts with oxygen gas to form water vapor. H 2 (g)+O 2 (g)  H 2 O (g)

13. Interactive Notes – Conservation of Mass Hydrogen gas reacts with oxygen gas to form water vapor. H 2 (g)+O 2 (g)  H 2 O (g) Particle drawings can also be drawn from chemical equations. Draw the particle drawing of the above equation (1 minute)

14. Interactive Notes – Conservation of Mass Hydrogen gas reacts with oxygen gas to form water vapor. H 2 (g)+O 2 (g)  H 2 O (g) Look at your particle drawing: Do you notice anything missing?

15. Interactive Notes – Conservation of Mass Hydrogen gas reacts with oxygen gas to form water vapor. H 2 (g)+O 2 (g)  H 2 O (g) Not every shape (atom) accounted for!

16. Interactive Notes – Conservation of Mass Hydrogen gas reacts with oxygen gas to form water vapor. 2H 2 (g)+O 2 (g)  2H 2 O (g) All shapes (atoms) accounted for!

17. Interactive Notes – Conservation of Mass -Chemical Reactions -Reactants (what you start with) on the left, products (what you end with) on the right -“+” means “reacts with.” Also means “and.” -“  ” means “produces,” “yields,” or “reacts to form”

18. Interactive Notes – Conservation of Mass -Chemical reactions show states of matter. -(g) means -(l) means -(s) means -(aq) means. This means dissolved in water. -NaCl (s) is different than NaCl (aq). In your notebook, what is the difference? (1 minute + signature)

19. Interactive Notes – Conservation of Mass Hydrogen gas reacts with oxygen gas to form water vapor. 2H 2 (g)+O 2 (g)  2H 2 O (g) The Numbers - Subscript (lower number) means how many atoms in that substance - Coefficient (beginning number) means how many of that substance you have

20. Interactive Notes – Conservation of Mass Hydrogen gas reacts with oxygen gas to form water vapor. 2H 2 (g)+O 2 (g)  2H 2 O (g) -For H 2 O substance, there are two hydrogens and one oxygen (subscript) -For the overall reaction, two H 2 O substances are produced (coefficient)

21. Practice! (20 minutes) For the chemical reactions on your hand-out: 1.Balance the equation with the correct coefficient next to each reactant and product 2.Use the blocks to demonstrate how each atom on the reactant side is rearranged on the product side (LCM) 3.Draw particle pictures to represent equation (Use whatever shapes/symbols/colors you want) 4.Get my initials