Download Elements can be broken down by chemical reactions

Grade 9 Applied Science – Unit 2 – Chemistry
Physical and Chemical Properties - Physical and Chemical Change
Everything is either matter or energy. According to
the Classification of Matter, matter falls into one of
three categories:
 Elements
 Compounds
 Mixtures.
Further, mixtures can be classified as homogeneous
(i.e., appears as one thing but it is not) or
heterogeneous (i.e., appears as more than one thing).
Properties
All substances have properties that can be used to
identify them. For example we can identify a person
by their face, voice, height, finger prints, DNA, etc.
Matter has two basic types of properties: physical properties and chemical properties.
Physical properties
 Readily observable
 Includes colour, size, luster, density, taste, solubility, freezing point, melting point, physical state,
viscosity (…ability to flow), density, ductility (…ability to be stretched) and smell.
Chemical properties
 Only observed during a chemical reaction
 Describes what a substance does as it changes into one or more new substance(s).
 Includes heat of combustion, reactivity with water, pH and electromotive force.
Change
Matter undergoes change all of the time. Some changes are minor, like an increase in temperature. Other
changes are violent like the combustion (burning) of a piece of wood.
Change also has two categories: physical change and chemical change. The factor distinguishing one
category form the other is whether or not a particular change results in the production of a new substance.
Physical change is a change that does NOT result in the production of a new substance. If you melt a
block of ice, you still have water (H2O) at the end of the change. If you break a bottle, you still have glass.
Painting a piece of wood will not make it stop being wood. Some common examples of physical changes
are melting, freezing, condensing, breaking, crushing, cutting, and bending.
Chemical change (chemical reactions) is a change that results in the production of another substance.
When you burn a log in a fireplace, you are carrying out a chemical reaction that releases carbon. When
you light your Bunsen burner in lab, you are carrying out a chemical reaction that produces water and
carbon dioxide. Common examples of chemical changes are digestion, respiration, photosynthesis, burning
and decomposition.
Changes in Matter - Physical and Chemical Change
Identify the “type” of change
Event
Melting ice
Baking
Burning paper
Breaking glass
Metal rusting
Cutting copper wire
Tearing Paper
Decomposition of old leaves
Painting wood
Physical / Chemical
Reason
Answer Sheet
Event
Physical / Chemical
Reason
Melting ice
P
No new product
Baking
C
New product produced
Burning paper
C
New product produced
Breaking glass
P
No new product
Metal rusting
C
New product produced
Cutting copper wire
P
No new product
Tearing Paper
P
No new product
Decomposition of old leaves
C
New product produced
Painting wood
P
No new product