Physical & Chemical
Properties
Scientists use characteristic
properties to identify matter
Physical Properties
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Many physical properties can be observed
or measured
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Mass, volume, density (mass/volume)
Color, shape, odor, texture
Melting, boiling point
Strength, hardness,
Magnetism
Ability to conduct electricity or heat
State of matter (solid, liquid, gas)
Specific Temperatures of Phase
Changes
Substance
Water
Gold
Carbon
Mercury
Nitrogen
Oxygen
NaCl
Melting Pt oC
0
1063
3550
-39
-209
-218
801
Boiling Pt oC
100
2970
4827
357
-196
-183
1413
Density
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All matter has mass, volume & density
Density determines whether an object will
float or sink
Density is the amount of mass in a volume
Density = mass/volume
D=m/V
Density Examples
Substance
Air
Helium
Water
Ice
Steel
Iron
Chemical
Formula Density in g/cm3
mixture
He
H20
H20
mixture
Fe
0.00129
0.00018
1.0
0.92
7.8
7.86
Physical properties help to
determine uses
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Copper used in electrical power lines
Antifreeze (ethylene glycol) remains a
liquid at temperature that would freeze or
oil water in a car radiator
Aluminum foil is lightweight, yet durable,
water resistant and flexible
Chemical Properties
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Describes how a substance reacts
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Reactivity – the ability of a substance to
combine chemically with another substance
(oxygen, acid, water or other substances)
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Iron reacts with oxygen to make rust Fe2O3
Flammability – the ability of a substance to
react in the presence of oxygen and burn
when exposed to a flame
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Wood is flammable
Gold is nonflammable
Comparisons
Substance
Physical
Chemical
Helium
less dense air
nonflammable
Wood
grainy texture
flammable
Baking Soda
white powder
reacts w/vinegar
Rubbing alcohol
clear liquid
flammable
Iron
malleable
reacts with oxygen
Physical Change
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A change of matter from one form to
another without a change in chemical
properties
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Torn paper
Melting ice
Crushing a can
Sanding wood
Dissolving sugar
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Although a physical change takes place, a
substance will maintain its chemical
properties
Melting, freezing and evaporation - all
changes of state - are physical changes
because the identity of the substance does
not change
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ice, water, steam – all are water!
Physical changes are often easily reversed.
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Mixtures can be separated using physical
and chemical properties.
Physical properties such as solubility,
magnetism, density and size can help
separate mixtures.
Chemical change
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A change that occurs when a substance
changes composition by forming one or
more new substances.
Chemical changes are always
accompanied by physical changes.
Evidence of Chemical Reaction
Chemical change or “reactivity” results in
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Temperature change (always)
Flame or light or explosion
Change color
Bubbling (gasses) [NOT BOILING]
Oxidation (rusting or tarnishing)
Solid formation (precipitation) [NOT FREEZING]