Classification of
Matter
Chapter 17
Section 1 Composition of Matter
A. Substance – either an element or a
compound
1. When all atoms in a substance are alike,
the substance is an element.
2. A compound is a substance with two
or more elements combined in a fixed
proportion.
B. Two or more substances that can be
easily separated by physical means form a
mixture.
1. Heterogeneous mixture – mixture of
different and easily distinguishable materials
2. Homogeneous mixture – contains two or
more gaseous, liquid, or solid substances
blended evenly; also called a solution
3. Colloid – heterogeneous mixture with
larger particles that never settle; colloids
scatter light in the Tyndall effect.
4. A heterogeneous mixture containing a
liquid in which visible particles settle is
called a suspension.
Section 2 Properties of Matter
A. Physical property- characteristics of
material which can be observed without
changing the identity of the substance in the
material; examples include color, shape, size,
melting point, and boiling point.
1. Appearance – physical description of a
substance.
2. Behavior – how a substance acts; for
example, magnetism, viscosity, ductility.
3. Physical properties such as size and
magnetism can be use to separate
mixtures.
B. Physical change – change in a substance’s
size, shape, or state of matter.
1. Substance does not change identity
when it undergoes a physical change.
2. Distillation is a process for separating
a mixture by evaporating a liquid and
condensing its vapor.
C. Chemical property – characteristics of
a substance indicating that it can change
chemically; for example, flammability or
light sensitivity of a substance.
D. When one substance changes to another
substance, a chemical change has occurred.
1. Some chemical changes are indicated
by temperature change, smell, or bubbling
formation.
2. Other chemical changes occur very
slowly such as the formation of rust.
3. Chemical changes can be used to
separate substances such as metals from
their ores.
E. Weather if Earth’s surface involves
both physical and chemical changes.
1. Physical – big rocks split into smaller
ones; streams carry rock particles from
one location to another.
2. Chemical – Chemical changes can occur
in rocks when calcium carbonate in
limestone changes to calcium hydrogen
carbonate due to acid rain.
F. Law of Conservation of Mass – Mass
of all substances present before a chemical
change equals the mass of all substances
after the change.
1.
How does the law of conservation of mass apply to chemical
change?
a)
The mass of all substances present before a chemical change
equals the mass of all the substances remaining after the change.
b)
There is more mass present before a chemical change than
after the chemical change.
c)
There is less mass present before a chemical change than
after the chemical change.
d)
Mass disintegrates after a chemical reaction.
2.
Why is flammability a chemical property rather than a
physical property?
a)
Burning is a physical process.
b)
Burning changes the substance into something completely
different.
c)
Burning does not change the physical properties of the
substance.
d)
Fire is considered plasma.
3.
a)
b)
c)
d)
You know you have a physical change if…
the substance gives off heat
the substance gives off an odor
the substance does not change color
the substance shows bubbles forming
4.
In terms of substances, why would evaporation of water be a
physical change and not a chemical change?
a)
The make up of water changes.
b)
You can smell water when it evaporates.
c)
Water changes color when it evaporates.
d)
The make up of water does not change.