Physical properties and changes are essential concepts in science, particularly in understanding matter. This unit focuses on qualitative and quantitative properties, such as color, mass, and temperature, and how they help identify substances. Students will explore examples like bicycles and running shoes to analyze their physical characteristics. The unit also discusses physical changes, including states of matter and dissolving processes. Ideal for Grade 9 science students, this resource provides a comprehensive overview of key principles in physical science.

Key Points

  • Explains qualitative and quantitative physical properties of matter.
  • Covers examples of physical properties using bicycles and running shoes.
  • Discusses physical changes, including state changes and dissolving.
  • Includes practical activities for hands-on learning about physical properties.
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5.2
Physical Properties
If you have ever lost a piece of luggage at the airport, you know how
important it is to provide a good description of its appearance. You need
to report its colour, shape, size, and any other identifi able features, such as
the colourful name tag that you could use to distinguish your luggage from
hundreds of other items (Figure 1). When you describe your luggage in this
way, you are reporting the physical properties of your lost item.
Figure 1 Colour, shape, and size are
physical properties that help identify
objects and substances. Some of these
pieces of luggage are easy to identify
because of their physical properties.
Figure 2 Physical properties include qualitative
observations such as colour, odour, and texture.
Figure 3 Temperature is a quantitative property
that tells us about the energy of particles in a
substance.
Physical properties give us information about what the substance is like.
You can determine a physical property by simply observing the substance
using your fi ve senses and measuring instruments. Determining physical
properties does not involve changing the composition of the substance.
We make direct observations when we are asked to determine the physical
properties of a substance. For example, you might describe the substance
in Figure 2 as white, odourless, and powdery. Th ese descriptions tell us
something about the appearance of the substance—in this case, how it looks,
smells, and feels. We make these observations using our fi ve senses. Any
property that does not provide numerical information about the substance is
called a qualitative property. Further, we may take some measurements and
note that the substance has a mass of 10.0 g and is at a temperature of 25 °C.
Th ese measured physical properties give us numerical information about
the substance. Th ese types of information are quantitative properties of the
substance (Figure 3).
qualitative property a property of a
substance that is not measured and does
not have a numerical value, such as
colour, odour, and texture
quantitative property a property of a
substance that is measured and has a
numerical value, such as temperature,
height, and mass
physical property a characteristic of
a substance that can be determined
without changing the composition of
that substance
Condensing the Original Text
When writing a summary, fi nd ways to
condense the original text. Sometimes
several specifi c words can be replaced
by a general word. For example, “colour,
shape, size, and any other identifi able
features” can be shortened to “physical
properties.”
WRITING TIP
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Observations that a bicycle has a mass of 10 kg and is 2.0 m long
are quantitative physical properties of the bicycle because they include
a measurement. Qualitative physical properties of the bicycle are not
measured and include that it is red, shiny, and rigid (Figure 4).
So far, we do not have any information about what will happen if we leave
this bike out in the rain or whether a cola drink would eff ectively remove
rust from the bike. Th ese properties are chemical properties of the bike,
which involve changing the bike’s composition. Chemical properties are
discussed in Section 5.3.
SKILLS: Observing, Analyzing, Evaluating, Communicating
SKILLS HANDBOOK
3.B.6.
Do you spend time and effort shopping for the ultimate running
shoe (Figure 5)? What physical factors infl uence your decision?
Perhaps comfort and support take priority over breathability and
weight. Of course, style and colour are important as well.
In this activity, you will closely examine a running shoe. You will
note how the physical properties of the different materials in it
determine their specifi c function in the shoe.
Equipment and Materials: running shoe
1. Make a table with three columns and record the following
information:
(a) In the fi rst column, list all the different materials used to
make each part of the shoe; for example, rubber soles.
(b) In the second column, record the physical properties of
each material listed; for example, waterproof, fl exible.
(c) In the third column, describe the function of each
physical property you listed in part (b); for example,
keeps the shoe dry, allows the foot to bend.
2. List at least fi ve different quantitative properties of your shoe.
A. Of the physical properties that you listed, which are the most
useful in the running shoe?
A
B. From what you know about the different materials that make
up a running shoe, which ones might present a problem to
the environment when the shoes are eventually discarded?
Explain your answer.
A
C
C. There are different brands of running shoes, and they vary
in price. What factors might infl uence the various prices?
Compare the physical properties of the materials of several
different brands of running shoes. Do they vary signifi cantly?
What other factors determine the retail price of running
shoes? How important should these other factors be when
choosing a pair of running shoes? Make a priority list of
factors you will take into consideration when choosing your
next pair of running shoes.
A
TTRY THIS
CLOSE-UP OF A RUNNING SHOE
Figure 5 A running shoe has important physical properties that
enhance its function.
Figure 4 A bicycle has both quantitative
and qualitative physical properties.
Restating the Main Idea
When you restate the author’s main
idea in the topic sentence of your
summary, you say it in words that you
understand. For example, if the author
says that “some physical properties
are particularly useful in describing
and categorizing substances,” you
might restate this main idea by saying
“physical properties are used to
describe substances.”
WRITING TIP
Some physical properties are particularly useful in describing and
categorizing substances. Common qualitative physical properties include
colour, odour, taste, and texture. Some of the other physical properties of
matter are
•lustre—shininessordullness;manysilverobjectshaveahighlustre
(Figure 6), whereas a rusty nail has low lustre
•opticalclarity—theabilitytoallowlightthrough(Figure7);thinblue
glass is clear and transparent, frosted glass is translucent, and a brick
wall is opaque
•brittleness—breakabilityorflexibility;glassisbrittle(Figure8)whereas
modelling clay is fl exible
•viscosity—theabilityofasubstancetofloworpourreadily;molassesis
viscous (Figure 9) whereas water is less viscous
viscosity the degree to which a
fl uid resists fl ow
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•hardness—therelativeabilitytoscratchorbescratchedbyanother
substance(Figure10);waxislowonthehardnessscale,whereasdiamonds
are high on the scale because they scratch nearly all other substances
•malleability—theabilityofasubstancetobehammeredintoathinner
sheetormolded(Figure11);silverismalleablewhereasglassbreakseasily
•ductility—theabilityofasubstancetobedrawn(pulled)intoafiner
strand;piecesofcoppercanbedrawnintothinwiresandareconsidered
ductile (Figure 12)
•electricalconductivity—theabilityofasubstancetoallowanelectric
currenttopassthroughit;copperwireshavehighconductivity,whereas
plastics do not (Figure 13)
Figure 6 This shiny kettle has
high lustre.
Figure 7 The optical clarity
of this window allows a lot of
sunlight into the room.
Figure 8 Glass is brittle and
cracks easily.
Figure 9 Molasses is viscous.
Figure 10 The dark crystal
is hard.
Figure 11 This metal is
malleable because it can be
made into sheets.
Figure 12 Copper wire is
considered ductile.
Figure 13 The copper wires have
high conductivity but the plastic
switch does not.
As you will learn in Section 5.6, several quantitative physical properties
are easy to measure and provide a useful method for identifying a substance.
These properties include melting point and boiling point, as well as density.
Physical Changes
If you take a piece of paper and fold it into a paper crane, does the paper
undergo a chemical or a physical change? It is true that the paper crane
appears to be a new object, but the composition of the paper is not changed.
It is still paper, although with a different shape and size (Figure 14). This
change is a physical change. In a physical change, the composition of the
substance remains exactly the same. No new substances are made.
Consider a change of state. If you heat an ice cube until it melts, does it
undergo a chemical or a physical change? The ice cube was a cold solid, and
now it has changed into a cold liquid. Was a new substance produced?
physical change a change in which the
composition of the substance remains
unaltered and no new substances are
produced
Figure 14 It’s a bird! It’s a plane! Yes,
but it’s still paper.
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FAQs

What are qualitative and quantitative physical properties?
Qualitative physical properties are characteristics that can be observed but not measured, such as color and texture. Quantitative physical properties, on the other hand, involve measurements and numerical values, like mass and temperature. Understanding both types of properties is crucial for identifying and categorizing substances in science.
How do physical changes differ from chemical changes?
Physical changes involve alterations in the form or appearance of a substance without changing its chemical composition. For example, melting ice into water is a physical change, as the substance remains H2O. In contrast, chemical changes result in the formation of new substances, such as rusting iron or burning wood.
What examples illustrate physical properties in everyday objects?
Everyday objects like bicycles and running shoes provide clear examples of physical properties. A bicycle can be described by its color, mass, and length, while a running shoe's materials can be evaluated for flexibility and waterproofing. These observations help in understanding how physical properties affect functionality.
What is the significance of understanding physical properties in science?
Understanding physical properties is essential for identifying substances and predicting their behavior in different conditions. It allows scientists and students to categorize materials based on observable characteristics, which is fundamental in fields like chemistry and physics. This knowledge is also applicable in everyday life, such as when selecting materials for specific purposes.
What activities are included in this unit for learning about physical properties?
The unit includes hands-on activities that encourage students to examine various materials and their physical properties. For instance, students might analyze the components of a running shoe, noting the materials used and their functions. Such practical exercises reinforce theoretical knowledge and enhance critical thinking skills.

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