2013 Pure Substances and Mixtures

Today’s Starting Point
1. What is an intensive property of matter?
List two examples of intensive properties.
Do not depend upon the amount
of matter present; color, density
2. What is an extensive property of matter?
List two examples of extensive properties.
Do depend upon the amount of
matter present; mass, volume
Today’s Starting Point
3. Compare these two
elephants. What would be
an intensive property of the
elephants? What would be
an extensive property of
the elephants?
By the end of the class period
today I will be able to…
Identify a piece of matter as an
element, compound,
homogeneous, or
heterogeneous mixture based
upon its properties
Pure Substances
 Composition is the same throughout and
does not vary from sample to sample.
 CANNOT be broken down by physical
 Can be an element or compound.
Definition: substances in their
simplest forms
Cannot be broken down by a
physical or chemical change
Found on the periodic table
Made up of one type of atom
Examples of Elements:
 Hydrogen
 Carbon
 Lithium
 Gold
What are two other examples of elements not listed above?
What do all elements have in common?
 Definition: substance formed by the
chemical combination of two or more
 can be broken into simpler substances by
a chemical change
= Compound
Law of Definite Proportions
 A compound is always composed of the
same elements in the same proportions.
In other words, Carbon Dioxide (CO2) is always
composed of 1 atom of C and 2 atoms of O.
If there are different amounts of carbon or oxygen,
it is no longer carbon dioxide.
More Examples of Compounds
 Definition: two or more pure
substances (elements or compounds)
that are mixed together but NOT
joined chemically
 NOT a pure substance
 Examples: The air we breath,
gasoline for cars, the sidewalk on
which we walk
Homogeneous Mixtures
 Uniform in composition and appearance
 Same proportion of components
 Consists of two or more substances in the
same phase
 Also called solutions
Heterogeneous Mixtures
 variable appearance and composition
Raise ‘em Up!
Look at the following example
and with your partner
determine if it is a
heterogeneous mixture,
homogeneous mixture,
element, or compound
Chicken Noodle Soup
Pure Water
Tap Water
Pure Gold
Kool Aid has mass
and takes up space
Can be
separated by
water to