2.80
Chapter 2: Properties of Matter
(Matter: all of the stuff that makes up everything.)

This is what
you need to
know to pass
the chapter 2
test!
There are different types of changes in matter that happen.
Examples
2.1: Classifying Matter: anything that has mass and takes up space.
The Big Question: There’s a lot of different kinds of “stuff”
in this great big world; how do we tell or describe what’s what?
I. Pure Substances: Matter that always has exactly the same
composition, or simply a substance.
 Every sample of a given substance has the same properties
because a substance has a fixed, uniform composition.
 Substance can be classified into two categories: elements &
compounds.
A: Elements: a substance that cannot be broken down into simpler
substances.
 An atom is the smallest particle of an element.
 An element has a fixed composition because it contains
only on type of atom.
B: Compounds: a substance that is made from two or more simpler
substances and can be broken down into those simpler substances.
 The simpler substances are either elements or other
compounds.
 A compound always contains 2 or more elements joined
in a fixed proportion.
Examples
II. Mixtures: tend to retain some of the properties of their individual
substances.
 The properties of a mixture can vary because the composition
of a mixture is not fixed.
 There are 2 types of mixtures: heterogeneous & homogeneous
A: Heterogeneous Mixtures: the parts of the mixture are noticeably
different from one another.
B: Homogeneous Mixtures: the substances are so evenly distributed
that it is difficult to distinguish one substance in the mixture from
another.
Type of Matter
Summary of the Types of Matter
Definition (own words)
Examples
Homogeneous
Mixture
Heterogeneous
Mixture
Element
Compound
III. Solutions, Suspensions, and Colloids: based on the size of its
largest particles, a mixture can be classified as a solution, a
suspension, or a colloid.
A: Solutions: when substances dissolve and form a homogeneous
mixture.
 The particles in a solution are too small to settle out of the
solution, be trapped by a filter, or scatter light.
B: Suspensions: is a heterogeneous mixture that separates into layers
over time.
 Because the particles are larger they can scatter light, look
cloudy, the particles settle out and can be filtered.
Examples
Solutions
Colloids
Suspensions
C. Colloids: contains some particles that are intermediate is size
between the small particles in a solution and the larger particles in a
suspension.
 The particles cannot be separated by a filter, they do not settle
out or form layers and they scatter light.
Properties of solutions, suspensions, and colloids
Approximate size
Solute particles
Can be separated by
of solute particles
Settle
filtering
0.01 – 1.0 nm
1.0 – 1,000 nm
>1000 nm
Particles
scatter light
2.2 Physical Properties
The Big Question: What observations will help us describe
all of this stuff?
I. Examples of Physical Properties:
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A physical property is any characteristic of a material that can
be observed or measured without changing the composition of
the substances in the material.
Those properties include size, shape, and state of the matter.
A: Viscosity: the tendency of a liquid to keep from
flowing, its resistance to flowing.
 Thick liquids (corn syrup, honey) have a
high viscosity.
 Thin liquids (water, vinegar) have a low
viscosity.
 Colder temp = more viscous
 Warmer temp = less viscous
B: Conductivity: a material’s ability to allow heat to flow.
 If a material is a good conductor of heat, it is usually also a
good conductor of electricity.
 Metals are good conductors of heat.
 Wood is not a good conductor of heat, it would be an insulator.
C: Malleability: is the ability of a solid to be hammered without
shattering.
 Most metals are malleable.
 Ice cubes & glass are not malleable.
 Solids that shatter when struck are brittle.
D: Hardness: measures a solid’s resistance to scratching.
 Diamond is the hardest natural substance found on Earth.
Examples
E: Melting and Boiling Points:
 Melting Point: the temperature at which a substance changes
from solid to liquid.
 Boiling Point: the temperature at which a substance boils.
F: Density: the ratio of the mass of a substance to its volume.
Density = Mass
Volume
D = M
V
Which would
you rather play
basketball with?
Using Physical Properties: they are used to identify a material, to
choose a material for a specific purpose, or to separate the substances
in a mixture,
Using Physical Properties to Separate Mixtures: 2 common
methods are:
A. Filtration: a process that separates materials based on the size of
their particles.
B. Distillation: a process that separates the substances in a solution
based on their boiling points.
Recognizing Physical Changes: they occur when some of the
properties of a material change, but the substances in the material
remain the same.
2.3 Chemical Properties
The Big Question: Sometimes when you mix stuff together,
stuff happens. What’s going on?
I. Observing Chemical Properties:
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
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A chemical property is any ability to produce a change in the
composition of matter.
Chemical properties can be observed only when the substances
in a sample of matter are changing into different substances.
Flammability and reactivity are 2 examples of chemical
properties.
Examples
A: Flammability: a material’s ability to burn in the presence of
oxygen.
B: Reactivity: the property that describes how readily a substance
combines chemically with other substances.
 The element oxygen is a highly reactive element.
 The element nitrogen has an extremely low reactivity.
II. Recognizing Chemical Changes
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A chemical change occurs when a
substance reacts and forms one or more
new substances. The breaking of bonds
in one
or more substances, and the reforming of
new bonds to create new substances.
You know a chemical change has
occurred when one or more starting
substances are mixed and you get
products (stuff) that appear to be
different from those starting substances.
Atoms are rearranged when chemical
changes occur.
You can use your powers of observation
to determine that a chemical change has taken place.
All chemical reactions involve the rearrangement of atoms
Some clues/evidence that a chemical change has occurred.
A: Change in Color: You mix some stuff
together and the turns a completely
different color (mix reactants, a reaction
occurs and you get a product).
B: Production of a Gas: (Think of eating a
lot of Bean Burritos!) You mix some stuff
and bubbles, a gas appears (mix reactants,
a reaction occurs and you get a product).
C: Formation of a Precipitate: You mix 2
liquids together and a solid forms and
separates (mix reactants, a reaction occurs
and you get a product).
 Precipitate: any solid that forms
and separates from a liquid mixture
D: Temperature Change: You mix 2 or
more things and they get hotter or colder
(mix reactants, a reaction occur and you get
a product).
Examples
E: Others:
III. So what is it: A Physical Change or a Chemical Change?
The Big Question: What’s the difference between a physical
change and a chemical change in matter? There are different types of
changes in matter that happen.

You need to ask yourself: are different substances present after
the change takes place?
o If YES: It’s a chemical change.
o If NO: It’s a physical change.

Physical Change: When mater undergoes a physical change,
the composition of the matter remains the same.

Chemical Change: When matter undergoes a chemical
change, the composition of the matter changes.

You know a chemical change has occurred when one or more
starting substances are mixed and you get products that appear
to be different from those starting substances.
Vocabulary Terms You Need To Know
Pure substance
Element
Atom
Compound
Heterogeneous mixture
Homogeneous mixture
Solution
Suspension
Colloid
Physical property
Viscosity
Conductivity
Malleability
Melting point
Boiling point
Filtration
Distillation
Physical change
Chemical property
Flammability
Reactivity
Chemical change
Precipitate
Think Visually
Composition
Of Matter
Does not
change during
Does
change during
Physical
Change
Such as
Such as
Melting
Matter
Element