classifying matter - pbworksscience3000.pbworks.com/w/file/fetch/86303467/chemistry 2... ·...
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Matter
Pure Substance:
Substance made up
of only one kind of
matter (particle).
Element:
Contains only one kind of atom.
The chemical symbol
has one capital letter.
Compound:
A pure substance that is made
of 2 or more different
elements that are combined
together chemically.
The chemical symbol has
2 or more capital letter.
Ex: NaClEx: Na
Example of a compound?
• Here you have a mixture of hydrogen and oxygen. They are
not chemically combined (joined) to each other though. Not
a compound.
HydrogenHydrogen
HydrogenHydrogen
Oxygen
Oxygen
Oxygen
Example of a compound?
• Water: H2O. Why is this a compound but not what was on the previous slide?
Hydrogen Hydrogen
Oxygen
“Chemically
combined”
• Because the elements on the previous slide were not chemically combined.
Water is now a new substance. It
is has different properties than
oxygen and hydrogen.
Mixture:
A combination of pure substances
(elements/compounds) that are NOT
chemically combined
(more than one type of particle).
Homogeneous (Homo = same):
The different substances
that make up the mixture
are not individually visible.
Also called a Solution.
Heterogeneous
(Hetero = different):
The different substances
that make up the mixture
are visible. Also called
mechanical mixture.
“Dissolving” Sugar in coffee is an
example of a solution because:
1) You cannot tell the sugar apart from the coffee (HOMOgeneous).
2) It is a mixture of two substances that are not chemically combined (coffee remains coffee and sugar remains sugar).
A salad is an example of a Mechanical
heterogeneous mixture because:
1) All the different substances that make up the salad are visible (HETEROgeneous).
2) It is a mixture of two or more substances that are not chemically combined (Lettuce remains lettuce, tomato remains tomato).
Heterogeneous: A type called
Suspension
• A suspension is a cloudy mixture in which clumps of a solid or droplets of a liquid are scattered throughout a liquid or gas.
• Muddy water, tomato juice, and orange juice with pulp are suspensions.
• The parts of a suspension may separate into layers if the suspension is not stirred.
Fresh Milk from the cow is a
suspension
• Farm-fresh milk
is a suspension.
If the milk is left
standing, the
fatty part (the
cream) floats to
the top and the
watery part sinks
to the bottom.
What about commercial milk?
• Commercially available milk does not separate. It is a special kind of suspension, called an emulsion, which has been treated to keep it from separating.
• In a process called homogenization, the milk is sprayed through very small openings. This breaks down the fat into droplets that are so tiny they stay suspended and NOT separate.
Classify the following as heterogeneous (suspension,
mechanical) or homogeneous (solution)
• Brass is made of copper
and zinc.
• They are not chemically
combined.
• Brass is a
compound/mixture.
• Brass is a homogeneous
mixture (solution)/
Heterogeneous mixture. A mixture of solids is called an
ALLOY
Classify the following as heterogeneous (suspension,
mechanical), homogeneous (solution), or pure substance
Classify the following as heterogeneous (suspension,
mechanical), homogeneous (solution), or pure substance
Classify the following as heterogeneous (suspension,
mechanical), homogeneous (solution), or pure substance
Cu
Classify the following as heterogeneous (suspension,
mechanical), homogeneous (solution), or pure substance
Classify the following as heterogeneous (suspension,
mechanical), homogeneous (solution), or pure substance
Classify the following as heterogeneous (suspension,
mechanical), homogeneous (solution), or pure substance
NaCl