1. Do Now:
Explain this joke.

2. The last 2 weeks we have…
 investigated how evidence of chemical reactions indicates that new substances with different properties are formed.

3. Evidence of a chemical reaction: (chemical change)
Production of a gas (bubbling, fizzing or foaming)
A change in temperature or light (an energy change)
Appearance of a precipitate (solid material)
A change in color

4. Chemical Reaction Dehydration of sugar…
Reactants
products
Physical properties
White crystal
To yield
Black crystal/powder and white gas
Chemical equation
C12H22O11   
12 C + 11 H2O (vapor)
Visual model +
Number of atoms
12 carbons 22 Hydrogen 11 oxygen
12 carbons 22 hydrogens 11 oxygens

5. Let’s make some visual models with SKITTLES
You will be able to…
8.5(D)  recognize that chemical formulas are used to identify substances and determine the number of atoms of each element in chemical formulas containing subscripts;
8.5(F)  recognize whether a chemical equation containing coefficients is balanced or not and how that relates to the law of conservation of mass.
Key
Red-Chlorine
Orange-Sodium
Yellow-Oxygen
Green-Hydrogen
Purple- Carbon

6. Review: How to make a molecule…
Formula
Visual model
H2O
Subscript
No Subscript,
There is only 1
atom of oxygen in
the molecule

7. Review: How to make a molecule…
Formula
Visual model
H2O
No Subscript,
There is only 1
atom of oxygen in
the molecule
Subscript
H2O2

8. Review: How to make a molecule…
Formula
Visual model
6 H2O
Coefficient- How many molecules you have.

9. H2O
1 molecule of H2O

10. 3 H2O
3 molecules of H2O

11. Let’s now model another chemical equation with our SKITTLES…
Reactants
products
Chemical equation
C + O2 
CO2
Visual model +
Word equation
To yield
Number of atoms
1 atom carbon reacts with molecule of oxygen
1 molecule of CO2
1 carbon oxygen
1 carbon oxygen

12. Is it a balanced equation? How do we know?
Reactants
products
Chemical equation
C + O2 
CO2
Visual model +
Word equation
Number of atoms
1 molecule CO2
1 atom carbon + 1 molecule oxygen
1 carbon oxygen
1 carbon oxygen

13. Law of Conservation of Mass
Matter is not created or destroyed, it just changes forms. In a chemical reaction…

14. More practice… Reactants products Chemical equation 2C + 2O2  3CO2
Visual model +
Word equation
To yield
Number of atoms
2 atoms carbon react with 2 molecule oxygen
3 molecules CO2
2 carbons oxygen
3 carbons oxygens
Is it balanced?

16. The model above is best represented by:
H2O
2OH
HOOH
H2O2

17. The above model shows:
10 atoms
2 molecules
2CH3Cl
All of the above

24. 6CO2+ 6H20+ Sun’s light C6H12O6+6O2
The above reaction…
is photosynthesis
Is respiration
Transforms radiant energy into chemical energy
Both a and c.

25. Organic Molecules all contain…
Sulfur
Carbon
Oxygen
nitrogen

26. All of the following are organic molecules except…
C6H12O6
CH4
C6H6O
H20