Engage Pretend you have a container of salt and a container of trail mix. How could you physically
separate the sodium and the chlorine from the salt? How could you separate the pieces in the
train mix?

• Atoms are the blocks of . An atom is the
unit of an element that maintains the properties of that
element.
o They combine with another to make different .
• A molecule is or more atoms that are
combined.
• Elements are made up of one or more of the same type of
that are chemically .
• Elements can not be broken down into substances.
• Compounds are molecules that are made up of different elements that are combined
.
o Compounds have a composition and their properties are
from the that make them up.
o A chemical bond is the that holds the
together.
• Mixtures are made up of and
but are not .
Combined with one another. They are combined.
Checkpoint #1
Identify each as an element, compound or mixture.
1. Hydrogen
2. Glucose
3. Milk
4. Cookie dough
5. Salt (NaCl)
• Pure Substances are or that have
definite physical and chemical properties.
o These properties can include: and
.
o All pure substances are made up of type of
(element or compound)?
o They cannot be broken down by changes. A
change would be required to break the bonds.
• Mixtures are divided into categories.
o Homogeneous mixtures are the same throughout. The have a
composition.
o Heterogeneous mixtures are the same throughout. They do
not have a composition.

Checkpoint #2
1. Soda
2. Air
3. Helium
4. Chlorine
5. Cold medicine
Checkpoint #3
Identify if the following mixtures are homogeneous or heterogeneous
1. Honey
2. Spaghetti with meatballs
3. Chocolate ice cream
4. Blood
5. Soil
• Colloids are mixtures that contain
particles that do not out.
• Suspensions are mixtures that have
particles that can be easily and .
• Solutions are mixtures in which one substance is
into another.
Bringing it Back
Think back to the container of salt and trail mix. Knowing what you know about pure
substances and mixtures, how could you separate the salt and trail mix?