4.4
Conduct an Investigation:
Measuring Mass and Volume
Page 104
PRESCRIBED LEARNING OUTCOMES
Time
• conduct investigations into properties of matter
45–60 min
KNOWLEDGE
Key Ideas
• matter is anything that has mass and volume; it is generally classified
as pure substances or mixtures
Matter is anything that has
mass and volume.
Skills and Processes
SKILLS AND ATTITUDES
• demonstrate curiosity, skepticism, creativity, open-mindedness, accuracy,
precision, honesty, and persistence as important scientific attributes
• use appropriate tools and techniques to gather, analyze, interpret, and
share information
• handle chemicals and equipment safely and responsibly
SCIENCE BACKGROUND
• Mass is a measure of how many
particles are in a substance, and
weight is a measure of the force of
gravity on those particles. A balance
is used to measure mass (in grams
or kilograms). A spring scale is used
to measure weight (in newtons). In
this investigation, students will be
measuring mass.
• Cubic metres (m3) and cubic
centimetres (cm3) are units of
volume. The volume of a liquid is
usually measured in capacity units,
such as litres (L) or millilitres (mL).
Capacity units and cubic units are
related to one another. You can easily
change from one unit to another. For
example, if you calculate the volume
of a container (dimensions: 2 cm 2
cm 2 cm) to be 8 cm3, you know
that it will hold 8 mL of water.
Observing
Communicating (sharing)
Communicating (recording)
Measuring and Reporting
Interpreting Data
Predicting
Lesson Materials
per pair
• safety goggles
• variety of regular solids
(e.g., textbook, dice, and
block of wood)
• variety of small irregular
solids (e.g., small rock,
small spoon, and metal nut)
• balance or scale
• ruler
• 100-mL graduated cylinder
or large measuring cup
• water
Capacity unit
Cubic unit
1 mL
1 cm3
Program Resources
1L
1000 cm3
1000 L
1 m3
BLM 0.0-8 Five-Column Table
Investigation Rubric 5:
Conduct an Investigation
Investigation Rubric 6:
Conduct an Investigation—
Self-Assessment
Nelson Science Probe 7
Web site
www.science.nelson.com
INVESTIGATION NOTES
Student Safety
Never put a hot object directly on the balance pan. When the mass
of a dry chemical is needed, the chemical should be placed on paper
or in a container. Never pour water or chemicals directly on the
balance pan. Remember to determine the mass of the paper or
container before adding the substance.
• Review with students the proper ways of using a balance and reading a
meniscus. Students may want to review Measurement and
Measurement Tools in the Skills Handbook.
NEL
Chapter 4 Matter can be described using properties.
197
• Before students begin the investigation, have them follow Reading
and Thinking Strategies: Check Understanding.
• To assess students, you may want to use or adapt Investigation
Rubric 5: Conduct an Investigation and/or Investigation Rubric 6:
Conduct an Investigation—Self-Assessment.
Question
• Review with students the methods for calculating mass and volume.
Refer to Section 4.3.
Materials
• Students should have all necessary materials before beginning their
experiments, and the materials should be checked to ensure they are
safe.
• Ensure students understand the differences between regular and
irregular solids. Show the class an example of each before proceeding
with the investigation.
Procedure
• Check for Misconceptions
– Identify: Students may think displacement is used only for measuring
irregular objects.
– Clarify: Explain that displacement can be used for both regular and
irregular objects. Most often, displacement is used for measuring
irregular objects that have difficult dimensions to measure (e.g.,
length, width, and/or height). Displacement refers to the volume of
liquid that is displaced by an object. If an object is added to a
container of water, the water level will rise because water is being
displaced. For example, if ice is added to a glass full of juice, the
juice will spill over the sides of the glass. The volume of liquid
displaced is equal to the volume of the object that is totally
immersed in it. The idea of displacement was first discovered by
Archimedes.
– Ask What They Think Now: Ask students to come up with other
examples of how we use displacement to measure things in everyday
life.
• Hand out BLM 0.0-8 Five-Column Table for recording data.
• Have students record their predictions or estimates in their tables.
• Have students determine their actual measurements, calculations, and
results for their tables.
• For irregular objects, have students use the displacement method to
find the volume. Remind students to tilt the graduated cylinder or
measuring cup and gently slide the solid into the water to avoid
splashing.
• Assign the investigation report and the Check Your Understanding
questions for homework.
198
Unit B: Chemistry
NEL
Analyze and Evaluate—Suggested Answers
1.
Answers may vary. Objects that are familiar to students and are
regular in shape are easier to estimate. Objects such as square blocks
and dice have regular shapes and straight sides, and their dimensions
can be estimated by looking at them.
2.
Answers may vary. Objects that are less familiar to students and are
irregular in shape are more difficult to estimate.
3. a)
b)
Objects placed in the water displace the water, and we can
determine the volume of water displaced.
With direct measurement you use only a measuring tool, such as
a ruler, to measure the dimensions of an object. These dimensions
are then used to directly calculate the volume of the object. With
indirect measurement, you don’t measure the actual object, you
measure the volume of water in a container before and after the
object is placed in the water, and then you use these measurements
to determine the volume of the object.
Math Connections
Have students find out
how much space they
each occupy (i.e., their
volumes). Ask them how
much water they would
displace if they were
submerged in an extra
large graduated cylinder.
Ask them to devise a
means to measure part of
their bodies using
displacement theory and
then proportionally
determine how much their
whole body would
displace and convert the
capacity measure to
volume. Ask them if their
answers make sense.
Apply and Extend—Suggested Answers
4.
Answers may vary. Examples are fluids for your car, ingredients in
baking and cooking, amounts of prescription medication, checkups
at the doctor’s office (mass), etc.
5.
First, find the volume of the original piece of modelling clay using the
displacement method (Volume of solid = (volume of water + solid) –
volume of water). Second, change the shape of the modelling clay
(e.g., roll it into a solid cylinder), and again place it in the graduated
cylinder. Record the change in the volume of the water to determine
the volume of the solid in its new shape. The volume should be the
same. To double check, split the piece of modelling clay into four or
five pieces, and roll the pieces into balls. Place all of the balls into the
graduated cylinder, and again determine the volume of water
displaced. Again the volume of water displaced should be the same.
This will prove that changing the shape of the clay does not change
the volume of the clay.
CHECK YOUR UNDERSTANDING—SUGGESTED ANSWERS
1. Objects are slid into the graduated cylinder because dropping objects may
splash some of the water out. Dropping objects may also damage or crack the
graduated cylinder.
If water splashed out of the graduated cylinder, the volume of water would
change, giving an inaccurate reading.
As long as the amount of water in the graduated cylinder remains the same
(i.e., none was splashed out), it doesn’t matter how the objects were placed in
the cylinder.
2. Displacement of water would not be a good method when the irregular object
floats (or is not completely submerged) or if the object dissolves (i.e., sugar or
salt).
NEL
Chapter 4
Matter can be described using properties.
199
4.4
SKILLS MENU
Questioning
Reading and Thinking Strategies: Check
Understanding
Conduct an Investigation
Observing
Predicting
Measuring
Hypothesizing
Classifying
Designing
Experiments
Inferring
Controlling
Variables
Interpreting
Data
Creating
Models
Communicating
Measuring Mass and Volume
In this investigation, you will use what you learned in section 4.3 to
determine the mass and volume of some common classroom objects
(Figure 1). First you will estimate the mass and volume of these
objects. Then you will check your estimates using direct measurement
or the displacement of water.
Have students work in pairs or small groups to read
the investigation together. Ask students to pause after
each text section. Clarify as needed, and discuss any
questions that arise or have been answered.
Procedure
the mass of each
1 Estimate
object in grams. Record
your estimates in your
notebook in a table
like the one below.
Data Table for Investigation 4.4
Object
Estimated
mass (g)
Actual
mass (g)
Estimated
volume
(cm3 or mL)
Actual
volume
(cm3 or mL)
textbook
Apply and Extend
eraser
4. Describe two everyday situations
Figure 1in which the measurement of
mass orsafety
volume is important.
How would you determine the mass and volume of these objects?
goggles
5. Imagine that you are provided with a scale, a sample of
Determine the actual
clay, a piece of string,
a graduated cylinder, and
Question
volume of each irregular
Estimate the volume of
could
youmass
use these
materials
to
some water (Figure 2). How
What
is the
and volume
of common
classroom objects?
solid in mL using
each object in either cm3
regular
prove that you can
change the shape of the clay without
or
mL. Record your estimates
displacement. Remember to
solids
changing the volume of the
clay?
Materials
in your table.
tilt the graduated cylinder or
• safety goggles
• balance or scale
measuring cup and gently
balance
Determine
the actual
of regular solids
• variety
• ruler
slide the solid into the water.
volume of(for
eachexample,
rectangular
textbook,
• 100-mL graduated cylinder
3
your
solid in cm . Record
dice, and
block of wood)Record youror large measuring cup
ruler to
Use the balance or scale
calculations,
measurements,
calculations,
of small irregular
• variety
• water
determine the actual mass measurements,
and results onsolids
your (for
table,example, small
and results in your table,
of each object in grams.
under “Actualrock,
volume.”
small spoon, andunder “Actual volume.”
Record your results
water in your graduated
cylinder
metal nut)
table, under “Actual mass.”
irregular
solidsmodelling
5
3
4
2
104
Unit B
Chemistry
NEL
Analyze and Evaluate
1. Which masses or volumes were you able to estimate most
accurately? Why?
2. Which masses or volumes did you estimate least accurately?
Why?
3. You used the displacement of water to measure the volumes of
irregular solids.
a) Explain why “displacement of water” is an appropriate name
Figure 2
for this method.
b) Why is this
method
an example
of indirect measurement?
CHECK
YOUR
UNDERSTANDING
NEL
4.4 Conduct
an Investigation
1. Why did you slide each object into the graduated cylinder
rather than
dropping it in? Would your results have changed if you had not slid all
the objects into the cylinder in the same way? Would you have still
obtained fair measurements? Explain your answer.
105
2. When would the displacement of water not be a good method for
finding the volume of an irregular object?
106
Unit B
Chemistry
Meeting Individual Needs
NEL
Extra Support
• Review mass and volume definitions before beginning this investigation.
ESL
• Ensure students understand the procedure before beginning. A teacher
demonstration of the procedure may be helpful. Listing the
order/sequence of events on the board is also useful.
• Have students draw a picture of the experimental set-up.
ASSESSMENT FOR LEARNING
What To Look For in Student Work
Suggestions for Teaching Students Who Are Having Difficulty
Evidence that students can
• estimate the mass of objects
• measure accurately (e.g., measure the mass
and volume of common classroom objects
correctly)
• display qualitative and quantitative data.
• create products that are complete
(e.g., table)
Limit the number of solids that students are asked to test. Present additional
examples of regular and irregular solids, and demonstrate how to measure them.
200
Unit B: Chemistry
NEL