What’s the MATTER:
Classify Changes &
Properties of Matter
Physical Change
Physical
A change in matter from one form
to another without changing its
chemical properties
(most can be reversed)
No change in atoms/molecules
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Physical Change
 Examples =
 Change in state or phase change
 Dissolving
 Compressing
 Light emission/absorption
 Electrons passing through metals
Physical Change
More Examples =
 boiling of a liquid
 melting of a solid
 dissolving a solid in a
liquid to give a
homogeneous mixture
 making a solution
2
Properties
 Every substance has a unique set of
properties (characteristics that identify
that substance)
 Physical Properties Properties that can be measured
without changing the identity and
composition of the substance
Properties of Matter
 2 Types:
 Extensive – depend on the amount of
the sample
 Always involves a number with unit
 Examples =
volume
mass
length
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Properties of Matter (cont.)
 Intensive – does not depend on the
amount of the sample
 Usually does not involve a number
 Examples =
density
melting, boiling point
malleability
ductility
color
odor
2
1
Chemical Change
Chemical
Bonds are made / broken
Change in oxidation states
Cl-1
Li
+1
Cl-1
4
Examples of Chemical Change
•Burning hydrogen (H2) in oxygen
(O2) gives H2O.
 Chemical change or chemical
reaction — transformation of
one or more atoms or
molecules into one or more
different molecules.
Sure Signs of a Chemical Change
“Chemists Get Practice Trying Labs”
 Color Change
 Gas Produced (not from
boiling!)
 Precipitate – a solid
formed by mixing two
liquids together
 Temperature Change
 Light
5
Chemical Properties
 Properties that describe the way a
substance may change to form other
substances
 Only observed when a chemical reaction
takes place
Chemical Property Examples





Combustible
Reactive with water or acid
Flammable
Corrosive
Decomposes in air
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Matter,
Classify Changes of Matter
Let’s see if you can:
1. Characterize various changes of matter
2. Recognize that a change of state in
matter is a physical change
Physical vs. Chemical Change
 Examples:
 melting
physical
 flame produced
chemical
 paper cut
physical
 dissolving salt
physical
in water
 tarnishes in air
chemical
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Physical vs. Chemical Change
 Examples:
 rusting iron
chemical
 mixing mud and
physical
water
 burning a log
chemical
 freezing water
physical
 grinding spices
physical
 A difference between physical
change and chemical change is that
1. chemical change involves energy while
physical change does not.
2. physical change involves energy while
chemical change does not.
3. different kinds of molecules are present
after a physical change but not after a
chemical change.
4. different kinds of molecules are present
after a chemical change but not after a
physical change
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In making a pizza,
which process involves
a chemical change?
1. Mixing spices for the
sauce
2. Slicing pepperoni for
the topping
3. Spreading cheese on
the pizza
4. Baking the dough to
form the crust
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