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Physical Science
Ch. 17
Section 1
Composition of Matter
Composition of Matter
• Substance
–An element or a compound
• Elements
–Substance with all the same
atoms
• Compounds
–Substance with atoms from
two or more elements
Mixtures
• Heterogeneous Mixture
–Where materials can
easily be distinguished
• Homogeneous Mixture
–Contains 2 or more
substances blended
evenly throughout
• Solution
–Homogeneous mixture where
particles are so small they cant be
seen with a microscope or filtered.
• Colloid
–Homogeneous mixture that never
settles
• Tyndall Effect
–Scattering of light by a colloid
• Suspension
–Heterogeneous mixture containing a
liquid where the particles settle out.
Matter
Substance
Element
Mixture
Homogeneous
Compound
Ex. Elements
H, O, Ca
Ex. H20
Hetrogeneous
solution
suspension
Ex. Coke
colloid
Ex. Jello
Ex. Mud
puddle
Section 2
Properties of Matter
• Physical Properties
–Characteristics of a material
which can be observed
without changing the
material
• Ex. include color, shape, size,
melting point, & boiling point
–Physical properties such as
size and magnetism can be
used to separate mixtures.
Physical Properties
• Appearance
–physical description of a
substance
• Behavior
–how a substance acts
•Ex. magnetism, viscosity,
ductility
• Physical change
–Change in substance’s size,
shape, or state of matter
• A Substance does not change
identity when it undergoes a
physical change
• Distillation
–a process for separating a
mixture by evaporating a
liquid & condensing its
vapor.
• Chemical property
–Characteristics of a
substance indicating
that it can change
chemically;
•Ex. Flammability or light
sensitivity of a substance
• Chemical Change
–When one substance changes
to another substance
• Can be indicated by
temperature change, bubble
formation, or smell
• Can occur very slowly such as
the formation of rust.
• Can be used to separate
substances such as metals
from their ores.
• Weathering of Earth’s surface
involves both physical and
chemical changes.
–Physical changes
• big rocks split into smaller ones;
streams carry rock particles
from one location to another
–Chemical changes
• can occur in rocks when calcium
carbonate in limestone changes
to calcium hydrogen carbonate
due to acid rain.
Law of Conservation of Mass
–Mass of all substances
present before a chemical
change equals the mass of
all substances after the
change.
–Mass can neither be created
or destroyed it just changes
forms