1. Chemical Formulas, Equations and Reactions Notes

2. Atom The smallest particle of any pure element. Only 1 atom
Example: 1 atom of H

3. Element
A substance made up of the SAME type of atom
Example: O2

4. Compound
-a substance made up of atoms of two or more DIFFERENT elements combined in a specific ratio
Ex. NaCl or H2O

5. Molecule -Group of 2 or more atoms
-Atoms may or may not be of the same element
EX. NaCl or O2

6. Atom Element Compound Molecule C, O, H, N C,C2, O, O2, H, H2, N,N2
CH4, H2O, CO2
CH4, H2O, H2, O2, CO2
2H2O, 3O2, 2CO2

8. Chemical Formula
-a way of describing the number of atoms that make up one molecule of a compound
Ex. C6H1206 H20

9. Subscript -the number of atoms of that particular element SUB-Below
EX. H20 or CH4

10. Coefficient EX. 2H2O 4Al2(SO4)3
-determines the number of molecules (groups) of the formula
-This number will be DISTRIBUTED just like in math. It applies to each element and is multiplied by each subscript to find the total number of atoms of each element and a total number of atoms in the molecule.
EX. 2H2O 4Al2(SO4)3

11. CH4 H C H H H

12. 2H20 H H H H O O

13. 4Fe2O3 NaClO 2FeCl3 ZnCl2 KMnO4 KClO3 3HgO 24F2 C6H5COOH 3Al2(SO2)3
Identify the Elements, give the number of atoms of each element, and the total number of atoms in the formula
4Fe2O3
NaClO
ZnCl2
KClO3
24F2
3Al2(SO2)3
2FeCl3
KMnO4
3HgO
C6H5COOH
2HCl

14. Chemical Reaction
-a change in which one or more chemical substances are rearranged to form different substances.

15. Reactants Products Chemical Equation
-a way to show a chemical reaction using chemical formulas.
-made up of reactants and products
Yields
Reactants
Products

16. Yield
the amount of product obtained as a result of a chemical reaction 

17. Components of chemical reaction
Products
-are indicated on the right side
-new substances created/PRODUCED in a chemical reaction
-Outputs
-Cake
Reactants
-are indicated on the left side
-substances that react in a chemical reaction
-inputs
-Ingredients

18. Example CH4 + 2O2  CO2 + 2H2O Reactants Products
Coefficient (# of molecules)
# of atoms of that element

19. Law of Conservation of Mass
-what goes into a chemical reaction will come out of a chemical reaction.
-atoms found on the reactants side will also be found on the products side. They will be broken apart and rearranged to create new substances.
-creates a “Balanced” equation
CH4 + 2O2  CO2 + 2H2O

20. Photosynthesis
6CO2 + 6H2O  C6H12O6 + O2

21. 4P + 5O2  P4O10 Mg + O2  MgO 2Al2O3  4Al + 3O2 2HgO  2Hg + O2
Modeling Balanced/Unbalanced Equations Identify whether the chemical reaction is balanced or unbalanced
4P + 5O2  P4O10
Mg + O2  MgO
2Al2O3  4Al + 3O2
2HgO  2Hg + O2
BaCl2 + H2SO4  BaSO4 + HCl

22. Identify Balanced Equations
2Fe + 3Cl2  2FeCl3
KMnO4 + HCl  KCl + MnCl2 + H2O + Cl2
HgO  Hg + O2
C6H5COOH + O2  CO2 + H2O
H2 + Cl2  2 HCl
2Fe + 3O2  Fe2O3
2NaOH + Cl2  NaCl + NaClO + H2O
Zn + 2HCl  ZnCl2 + H2
KClO3  KCl + O2
S8 + 24F2 8SF6

23. Signs of Chemical Changes

24. Chemical Property
-The ability of a substance to undergo a change that alters its identity.
-A characteristic that cannot be observed without altering the substance

25. Chemical Change Change in which the composition of a substance changes
Changes are not easily reversed

26. Signs of Chemical Changes
Change in Color
Change in
Temperature
3. Change in Odor
Bubbles-
Gas produced
5. Precipitate (solid)
is formed

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