1. Do Now: Take out notebook, homework, and pencil
Why is Na an element and NaCl a molecule?

2. Macaroni Salad Engagement Video
What is the smallest part of matter?
What are molecules made of?

3. Glue the notes page onto page 51

4. Molecules
A group of atoms bonded together, representing the smallest unit of a chemical compound
Made up of two or more atoms
The atoms can be the same or different
Examples of molecules:
O2 – oxygen gas
O3 – ozone gas
H2O - water molecule
CO2 – carbon dioxide
H2SO4 – sulfuric acid
Notice how some molecules are more complex than others

5. Compound
A chemical compound is a chemical substance formed when two or more different elements bond
The elements lose their individual chemical properties and the compound has new properties.
Chemical bonds are a result of the sharing or exchange of electrons among the atoms
2 Hydrogen atoms
1 Oxygen atom
Water Molecule

6. Quick INB Action – Molecules Practice
Element
Molecules
Compounds
1. Quickly sketch the 3 circles
2. Draw each object in the correct
circle.
© KeslerScience.com

7. Quick Action – Molecules Practice
Grab a partner and let’s practice. Is it a molecule or a compound?
Formula
Molecule
Compound
Element
Both
Compound and Molecule O2
NaCl
CH4 H2 H
Atoms elements and compounds
This would be a good short video to show at this time.
Write a rule that you can follow for determining the difference in a compound and a molecule?
Here is a hint… All ___________ can be ___________, but…..
© KeslerScience.com

8. Chemical Formula The recipe for a chemical substance
Tells the number of atoms of each element in a compound or molecule
Uses symbols for the elements present as well as how many there are in the form of subscripts
Chemical formula for water: H2O (circle the subscript)

9. Chemical Equation
A chemical equation is a shorthand way scientists use to describe a chemical reaction
In writing chemical equations the large number in front of a molecule’s symbol indicates the number of molecules participating in the reaction.
This number is called the coefficient
If no coefficient appears then only one molecule is present
2 H2 + O2 → 2H2O
Number of hydrogen molecules: 2
Number of oxygen molecules : 1
Number of water molecules: 2

10. Quick Action – Molecules Practice
Grab a partner and let’s practice. Count the molecules in each balanced equation.
1. CH4 + 2O CO2 + 2H _____ CH4 _______ O2 _______ CO2 _________H20
2. 2Fe +3Cl FeCl _____ Fe _____ Cl2 _____ FeCl3
3. P4O10 + H2O H3PO _____ P4O10 ______ H2O _____ H3PO4 1 2 1 2 2 3 2 1 1 4
© KeslerScience.com