Elements, Molecules,
Compounds, and Mixtures
Matter Exploration Unit
What is an element?
• consists of only one kind of atom
• cannot be broken down into a simpler type of matter by
either physical or chemical means
• can exist as one atom of the element by itself ( 1 atom of
Nitrogen) or together (2 atoms of Nitrogen)
Elements and Elements as Molecules
The element Argon
The element Nitrogen as a
molecule in the gas phase.
What is a molecule?
• A molecule is 2 or more atoms put together (bound together).
• May be made of the same or different atoms.
• Difficult to separate.
Compounds
• consists of atoms of two or more different elements bound together
• can be broken down into a simpler type of matter (elements) by chemical
means (but not by physical means)
• has properties that are different from its component elements
This is the a molecule of the compound water (gas phase). Oxygen atoms
are red and Hydrogen atoms are white. What do you call the individual
oxygen and hydrogen atoms?
Mixtures
• consists of two or more different elements and/or compounds physically
intermingled
• can be separated into its components by physical means (sorting, sifting,
using a magnet, changing density. Ex: From the video last week, how did
they separate iron filings from sand?)
Microscopic view of a gaseous mixture containing two
elements (argon and nitrogen) and a compound
(water).
Element,
Molecule,
Compound,
and/or
How can the
example be both
Mixture?
an element and a
molecule?
Check your answers:
•
•
•
•
•
•
•
A. 2 Molecules of an element (4 atoms)
B. 2 Molecules of a compound (6 atoms)
C. Mixture of 2 Molecules of 2 different elements
D. 2 Molecules of 2 compounds
E. 2 Molecules of an element
F. Mixture of 2 Molecules: 1 compound and 1 element
WHY are examples C and F mixtures and not all compounds?
Definition Example
Element
Molecule
Compound
Mixture
Picture
Elements, Molecules,
Compounds, and/or
Mixtures?
• How can an example
be both a compound
and a molecule?
Friday’s Activity
• How can we model elements, mixtures,
compounds, and molecules? What are
some materials we could use?
• Why do we need models?
Mini Marshmallow Lab
• If you are given the following materials, how could you model elements,
compounds, mixtures, and molecules? What would each material represent?
• Mini Marshmallows of different colors
(white, green, orange, pink, yellow)
• Toothpicks
Construction
• Step 1: CONSTRUCT 7 models of either elements, compounds, or mixtures
with the materials (mini marshmallows, toothpicks, plastic bags, markers).
• Step 2: DRAW a ROUGH sketch of EACH model in your journals (use a
legend and color code your models) after your build EACH model. You will
reuse some atoms.
• Step 3: Answer analysis questions in your journal.
• Step 4: Clean up or store materials.
Lab Rules
•
•
•
•
•
1. Wait for teacher instruction before touching lab materials. ALWAYS!
2. No horseplay! (Do not eat or throw the materials)
3. Clear your desk and make room for only the materials you need.
4. If in groups, share responsibilities of task. No putdowns, either.
5. When finished, return materials to their correct place.
Consequences
• Immediately removed from your group and assigned to write a 2 page paper
on how molecules affect your daily life.
• Participation points will be taken away.
Exit Slip
• Answer in your journal:
1. What are we doing for the Lab activity in Friday’s class?
2. What are the main Lab rules?
3. What are the consequences of not following the Lab or classroom rules?
4. What cooperative learning skills are important for this activity?