TEKS 5.5C
The student knows that matter has
measurable physical properties and those
properties determine how matter is
classified, changed, and used.
The student is expected to
demonstrate that some mixtures maintain
physical properties of their ingredients
such as iron filings and sand
What are some physical
properties of matter?

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
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Color
Texture
Odor
Conducts heat
Conducts
electricity

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Magnetic
Floats or sinks
Solubility
Boiling point
Melting point
Mass
Mixtures
Form when two or more
substances combine
 Keep their physical properties
 Can be separated by their
physical properties
 Do not form a new substance

Salad is an
example of a mixture

The lettuce and
vegetables do
not change
when mixed
Is cereal a mixture?
Yes…the properties
of the substances
do not change.
You can still see the
bananas, cereal,
and milk.
Is cake a mixture?
No…the properties
of the substances
change.
The eggs, flour, and
sugar change
when the cake is
mixed and baked.
Substances in a mixture can be
separated by their physical
properties…

Milk and cereal
can be
separated by
pouring the
mixture through
a strainer.
The cereal
would be
trapped in
the strainer
and the milk
would pass
through.
QUESTION:

How could you separate a
mixture of sand and
sawdust?
ANSWER:

Sawdust
Water
Sand
You can
separate the
sand from the
sawdust by
adding water.
The sand will
sink and the
sawdust will
float.
QUESTION:

Which scientific tool could
you use to separate a
mixture of iron filings and
sand?
ANSWER:

Iron
filings
You can
separate the
iron filings
from the sand
by using a
magnet.
Solutions are a special kind
of mixture

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One of the substances
dissolves in another
The substance spreads
out evenly
Solutions may be clear
or colored
You can make a solution when you
stir sugar into water. The sugar
dissolves and the water
remains clear.
Do all substances dissolve?
No…if you mix
sand with
water, the
sand does not
dissolve but
settles on the
bottom of the
glass.
Sand +
water
All solutions are mixtures
but not all mixtures are
solutions
Sugar + Water = ?
Mixture and a solution
 Sand + Water = ?
Mixture but not a solution

Other examples of solutions:
Soda = Gas + Liquid
 Jewelry = Solid + Solid
 Air = Gas + Gas

Solutions can be separated
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Most solutions can be
separated by evaporation.
To separate a saltwater
solution, let the water
evaporate.
Once the water is gone, the salt
will be left.
Challenge

You are given a mixture of
salt, sand, and gravel.
Design a plan to separate
this mixture? What tools
would you use? List your
steps in order.