Elements, Compounds and Mixtures
THE BIG IDEA…
Matter can be classified into elements,
compounds and mixtures
• In this section you will learn how
to explain the characteristics of
elements and gives examples
of these characteristics. You will
also learn how to identify and
classify elements as metals,
non-metals and metalloids
based on their properties.
States of Matter – 20 minutes
• Refer to Figure 4 in your book (page 93)
for help answering the following
• What do gold, iron, and aluminum have
• What do oxygen, neon, and sulfur have
• How is silicon different from aluminum or
• Describe pure substances.
• Describe the characteristics of
elements, and give examples.
• Explain how elements can be
• Classify elements according to
• Pure substance
Use your class hand out to draw a
representation of the word after you have
defined it in your notebook.
The purest substance
• An element is a pure substance that
cannot be separated into simpler
substances by physical or chemical
• A substance in which there is only one
type of particle is a pure substance.
• Elements are made of particles called
Identifying Elements by Their
• Elements are identified by using
their physical properties and
their chemical properties.
• An element may share a
property with another element
• properties can help you tell the
by Their Properties
Three major categories are:
• Metals are shiny, and they conduct
heat energy and electric current.
• Nonmetals conduct heat and
• Metalloids have properties of both
metals and nonmetals.
Non Metals Metalloids
• This section describes the
properties of compounds and
explains the differences
between compounds and
elements. You will also learn
about the properties and
importance of common
Elements and Compunds – 18 minutes
• The word compound refers to
something that consists of two
or more parts. How might you
make a compound using
elements? What are some
compounds that you know?
• Write your answer in your
•Explain how elements make up
•Describe the properties of compounds.
•Explain how a compound can be
broken down into its elements.
•Give examples of common
Compounds: Made of
• A compound is a pure substance
composed of two or more elements
that are chemically combined.
• Elements combine by reacting with
• A particle of a compound is a called
• Elements join in a specific ratio
according to their masses to form a
• Compounds can be broken down
into their elements or into simpler
compounds by chemical changes.
• Energy is needed for a chemical
change to happen.
• Two ways to add energy are to…
• apply heat
• apply an electric current.
• This section explains the
properties of mixtures. You will
learn how mixtures can be
separated. The concepts of
solutes, concentration, and
solvents are covered. You will
be able to compare solutions,
suspensions and colloids.
Mixtures and Solutions 18 minutes
• When you add sugar to coffee,
tea, iced tea, or lemonade, the
sugar disappears. What do you
think happens to the sugar?
• Write your answer in your
• Describe three properties of mixtures.
• Describe four methods of separating the parts
of a mixture.
• Analyze a solution in terms of its solute and
• Explain how concentration affects a solution.
• Describe the particles in a suspension.
• Explain how a colloid differs from a solution
and a suspension.
Properties of Mixtures
• A mixture is a combination of two or
more substances that are not
• No chemical changes happen when a
mixture is made.
• each substance has the same
chemical makeup it had before the
mixture was formed.
• Mixtures can be separated by using
• Physical changes do not change
the identities of the substances.
Properties of Mixtures,
• The components of a mixture do not
need to be mixed in a definite ratio.
• granite is a mixture of three minerals.
Different ratios of the minerals give
granite different colors, but the mixture
is always called granite.
• A solution is a mixture that appears to
be a single substance. The process in
which particles of substances separate
and spread evenly throughout a
mixture is known as dissolving.
• In a solution…
• the solute is the substance that is
• The solvent is the substance in which
the solute is dissolved.
Examples of Solutions…
Solutions may also be solids, such as steel.
Alloys (ancient India’s metallurgy) are solid
solutions of metals or nonmetals dissolved
• The particles in solutions are so
small that they never settle out.
• They also cannot be removed
• Light can pass through them
• A measure of the amount of solute
dissolved in a solvent is concentration.
• Solutions can be described as being
concentrated or dilute.
• But these two terms do not tell you the
amount of solute that is dissolved.
• Solubility is the ability of a solute to
dissolve in a solvent at a certain
Concentrations of Solutions,
• Gases become less soluble in
liquids as the temperature is
• Three ways to make a solute
dissolve faster are…
• mixing the solution
• heating the solution
• crushing the solute into smaller
• A suspension is a mixture in which
particles of a material are dispersed
throughout a liquid or a gas but are
large enough that they settle out.
• The particles in a suspension are large
enough to scatter or block light.
• A suspension can be separated by
passing it through a filter
• A colloid is a mixture in which the
particles are dispersed throughout but
are not heavy enough to settle out.
• Particles in a colloid are large
enough to scatter light.
• A colloid cannot be separated by
passing it through a filter.
• Concept Map