Unit 1: Matter and
Change
Review
1. Organize the following terms into a logical
flowchart/concept map
•
•
•
•
•
•
•
•
element
•
brass
•
matter
•
pure substances
•
gravel
•
seawater
•
homogenous mixture/solution
oxygen gas (O2)
sodium chloride (NaCl)
heterogeneous mixture
mixtures
compounds
iron
air
Review
2. Identify each of the following statements as
describing either a physical property or a
chemical property
• Water boils below 100C on top of a
mountain.
• Oxygen gas supports combustion.
• Lead is denser than aluminum.
• Sugar tastes sweet.
• Fertilizers help to increase agricultural
production.
Matter
Anything that has mass and takes up space
Pure Substance
Matter with an unique
and unchanging
composition
Element
Pure
substance that
chemical
cannot be
change
broken into
more simpler
substances
Mixtures
physical change
Compound
Atoms of two
or more
elements that
are chemically
united in a
fixed
proportion
A combination of 2 or
more pure
substances
Homogeneous
Mixture/Solutio
n
Mixture with a
uniform
composition
Heterogeneo
us
Mixture
Mixture does
not appear to
be the same
throughout
What is matter?
• Anything that takes up
space and has mass
• Matter or not?
– gold
– sound
– sunlight
– air
– water
– heat
– thoughts
Mass & Weight
• Mass is the measure of the amount of matter that
makes up an object
• Weight is a measure of the force of gravity on an object
– weight = mass x gravity
– weight varies depending on distance from the earth’s surface
• Because the value never changes, scientists use
mass, not weight to measure matter
(Pure) Substances
• A substance is a form of matter with an unique and
unchanging composition (composition doesn’t
change from sample to sample)
• Examples: Water, salt
• What about salt water?
• All pure substances are either elements or
compounds
Element
• An element is a pure substance that cannot be
broken into more simpler substances
• Examples: gold (Au), oxygen (O2)
• To date, there are 118 elements
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Compounds
• Compounds are substances composed of atoms
of two or more different elements that are
chemically united in a fixed proportion
– Water (H2O), sugar (sucrose, C12H22O11),
ammonia (NH3)
• Compounds can be separated back into its
elements (by chemical means)
– Electrolysis of water:
• 2H2O  2H2 + O2
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Matter
Anything that has mass and takes up space
Pure Substance
Matter with an unique
and unchanging
composition
Element
Pure
substance that
chemical
cannot be
change
broken into
more simpler
substances
Mixtures
physical change
Compound
Atoms of two
or more
elements that
are chemically
united in a
fixed
proportion
A combination of 2 or
more pure
substances
Homogeneous
Mixture/Solutio
n
Mixture with a
uniform
composition
Heterogeneo
us
Mixture
Mixture does
not appear to
be the same
throughout
What is a mixture?
• A mixture is a combination of two or more pure
substances
– the composition of a mixture can vary
– Substances in mixtures are physically but not
chemically combined
– each pure substance retains its individual chemical
properties
– Air is mostly a mixture of nitrogen, oxygen,and argon
• There are two types of mixtures:
– Heterogeneous and homogeneous
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Heterogeneous Mixture
• Heterogeneous mixtures do not appear to be
the same throughout and individual
substances remain distinct
• Example: Trail mix
Homogeneous
Mixture/Solutions
A homogeneous mixture has a uniform
composition throughout
– it always has a single phase (solid, liquid or
gas)
• Homogeneous mixtures are also called
solutions
• All solutions contain a solute and a
solvent
– solute is the substance present in smaller
quantity
– solvent is the substance present in greater
Examples of Solutions
solution
phase
solute
solvent
gas-gas
oxygen,
argon other
gases
nitrogen
Carbonated
water
liquid-gas
carbon
dioxide (CO2)
water
Vinegar
liquid-liquid
acetic acid
water
Brass
solid-solid
zinc
copper
Air
Properties of Matter
• Every pure substance has a unique set of
properties
• A property is a characteristic that allows us to
recognize a certain type of matter
Physical properties of water
clear liquid at room
temperature
boils at 100oC
freezes at 0oC
density at 4oC is 1.000 g/cm3
Physical properties
• Physical properties are
those properties that can
be measured without
changing the identity of
the substance:
– color, odor, melting point,
boiling point, density, hardness,
taste
• Physical properties are
either extensive or
intensive
Extensive property Intensive property
•A property that depends
on the amount of a
substance present
•Example: Mass, volume,
length
•value will change when
the amount of substance
changes: 1 mL of water
has a mass of 1 g while
the mass of 1 L has a
mass of 1000 g
•A property that is
independent of the
amount of substance
present
•Example: Density, boiling
point, melting Point
•value will not change
when the amount of
substance changes: The
density of water is always
1.00 g/mL
Chemical Properties
• Chemical properties describe the way a
substance may change or react to form other
substances
– Corrosion, flammability
• The inability of a substance to change is
also a chemical property
– Argon gas is inert
• To observe a chemical property a
chemical change must occur
Properties of Copper
Physical properties
reddish brown, shiny
good conductor of heat
Chemical properties
Forms a green copper
carbonate compound
when in contact with
moist air
Forms new substances
when combined with
nitric & sulfuric acid
Density = 8.92 g/cm3
Melting point = 1085oC
Boiling Point = 2570oC
Forms deep blue
solution when in
contact with ammonia
Changes in Matter
• A physical change is a change that
alters the appearance of the substance
drastically but leaves its composition
unchanged:
– bend, grind, split, crush, boil, freeze, melt,
vaporize
Chemical Change (Chemical
Reaction)
• In a chemical change a substance is transformed
into a chemically different substance
– When hydrogen burns in air it reacts with
oxygen to form water
• The new substances formed have different
compositions and different properties
• Terms: Explode, rust, oxidize, corrode, tarnish,
ferment, burn, rot etc.
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Evidence of Chemical Change
• Formation of a
gas or solid
• Color change
• Energy change
• odor
Physical or chemical change?
• Plants use carbon dioxide and water to
make sugar.
• On a cold day, water vapor in the air
forms frost.
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