LESSON 25: Capillary Carnations
ESTIMATED TIME Setup: 5–10 minutes | Procedure: Allow at least 24 hours to make periodic observations.
• DESCRIPTION
• MATERIALS
Place white carnations in colored water to make the
flower petals change color.
• OBJECTIVE
This lesson demonstrates capillary action in plants and
introduces the forces involved in the process. Students
use food coloring to help visualize the movement of
water into and through a plant. The lesson can be
extended to discuss the molecular structure and
properties of water.
o White
carnation flowers
Clear plastic cups
o Water
o Food coloring
o Scissors and/or a knife
o
Always remember to use the appropriate safety
equipment when conducting your experiment.
Refer to the Safety First section in the Resource Guide
on pages 421–423 for more detailed information about
safety in the classroom.
• CONTENT TOPICS
Scientific inquiry; states of matter; properties of
matter; attractive forces (surface tension, adhesion,
cohesion)
Jump ahead to page 308 to view the
Experimental Procedure.
NATIONAL SCIENCE EDUCATION STANDARDS SUBJECT MATTER
This lesson applies both Dimension 1: Scientific and Engineering Practices and Dimension 2: Crosscutting Concepts
from “A Framework for K–12 Science Education,” established as a guide for the updated National Science Education
Standards. In addition, this lesson covers the following Disciplinary Core Ideas from that framework:
• PS1.A: Structure and Properties of Matter
• PS2.A: Forces and Motion
• LS1.A: Structure and Function
• ETS2.B: Influence of Engineering, Technology, and Science on Society and the Natural World
(see Analysis & Conclusion)
OBSERVATION & RESEARCH
BACKGROUND
Matter exists primarily as a solid, liquid, or gas on the
earth. Solids have a definite volume and a definite shape.
Examples of solids are chairs, books, and trees. Liquids
have a definite volume but no definite shape. Examples of
liquids are water and orange juice. Gases have no definite
shape and no definite volume. Examples of gases are the
oxygen we breathe and the helium that fills balloons.
Capillary action, or capillarity, is the movement of liquids
upward through a narrow tube, cylinder, or permeable
substance because of the cohesive and adhesive forces
interacting between the liquid and the surface. Cohesion
is the attractive force that exists between like particles in
a certain liquid. (It’s the attraction that causes like
molecules to stick together.) Thus, water molecules are
attracted to other water molecules.
Along with differences in shape and volume, the
different states of matter have other unique properties.
For example, capillary action and surface tension are
unique properties of liquids.
Likewise, surface tension is a property of liquids that
describes the attraction of liquid particles at the surface.
The strong attraction (cohesion) of particles at the
surface of the liquid creates a surface “film” that makes
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LESSON 25: Capillary Carnations
moving an object through the surface of a liquid more
difficult than moving the object when it is completely
submerged in the liquid. Surface tension is also the
reason liquids tend to keep a low surface area. For
example, water droplets will tend to form into a sphere
rather than spreading out flat.
Conversely, adhesion is
the force of attraction
between unlike
molecules. It’s the
In ancient Greece,
force that causes
water molecules to
carnations were used to
stick to the inside
make ceremonial crowns.
of a glass. The
forces of capillary
action are strong
enough to move the liquid
upward against the force of gravity.
Fun Fact
All plants need water to survive, and most plants get
that water from the soil. Capillary action helps to move
water, and the nutrients dissolved in the water, up into
the plant’s roots and through all parts of the plant.
The water gets into the plant’s roots and adheres to the
plant tissue. The plant tissue attracts the water molecules
(because of adhesion), pulling the water up into the
plant. As one water molecule climbs, the cohesive
attraction to other water molecules pulls those molecules
up the stem as well. Why does all the water move
upward in the entire stem, rather than just some water
molecules moving upward along the edges? The surface
tension of the water keeps the surface intact, so the
whole liquid surface is dragged upward, pulling the rest
of the water molecules upward behind it.
In this experiment, the adhesive and cohesive forces pull
the water up into the carnation against the force of
gravity. This action can be proven by using food
coloring. The food coloring is drawn upward into the
plant and its petals with the water.
FORMULAS & EQUATIONS
Water is a liquid substance that is essential to the
survival of plants and animals.
The chemical formula for water is H2O.
This formula illustrates that a molecule of water is
comprised of two hydrogen atoms and one oxygen atom.
CONNECT TO THE YOU BE THE
CHEMIST CHALLENGE
For additional background information, please
review CEF’s Challenge study materials online at
http://www.chemed.org/ybtc/challenge/study.aspx.
• Additional information on states and properties of
matter, including surface tension, can be found in
the Classification of Matter section of CEF’s
Passport to Science Exploration: The Core of
Chemistry.
HYPOTHESIS
uWhen the stems of white carnation
flowers are placed in colored water, the
colored water will move up through the plant,
causing the petals to change color.
DIFFERENTIATION IN THE CLASSROOM
LOWER GRADE LEVELS/BEGINNERS
Perform the experiment as described on page 308, but
spend more time on the states and properties of matter.
Show pictures of different items—a chair, milk, a balloon.
(A balloon is a solid, but what’s inside?) Ask the students
to identify the states of matter, and describe the
differences between the states.
Likewise, focus more on the different properties of matter,
specifically the properties of liquids. Pour a little water on
a desk to illustrate the cohesive attraction of water
molecules. The water will form droplets. Then tilt the
desk slowly so that the water flows off the edge. Does it
linger at the side of the desk before falling to the ground?
Discuss how cohesion and adhesion play a part.
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LESSON 25: Capillary Carnations
DIFFERENTIATION IN THE CLASSROOM
HIGHER GRADE LEVELS/ADVANCED STUDENTS
DESCRIPTION
Place white carnations in colored water to make the
flower petals change color.
OBJECTIVE
This lesson demonstrates capillary action in plants and
explores the structure of plants and properties of water.
Students use food coloring to help visualize the
movement of water into and through a plant.
OBSERVATION & RESEARCH
Matter exists primarily in three states on the earth—solid,
liquid, or gas. Each state of matter has unique properties.
The properties of matter are characteristics that describe
a particular substance. For example, solids have a definite
shape. Likewise, liquids are often described by certain
unique properties, such as surface tension.
Capillary action, or capillarity, is the movement of liquids
upward through a narrow tube, cylinder, or permeable
substance because of the cohesive and adhesive forces
interacting between the liquid and the surface. Cohesion
is the attractive force that exists between like particles in
a certain liquid. (It’s the attraction that causes like
molecules to stick together.)
Water molecules are strongly attracted to one another.
Water molecules are polar molecules. Polar substances
are made up of particles that have an uneven distribution
of electrons, creating a negative and a positive side. The
oxygen atom in a water molecule has a partial negative
charge, and the hydrogen atoms have partial positive
charges. Because “opposites attract,” the negatively
charged oxygen atom attracts the positively charged
hydrogen atoms in other water molecules. When the
molecules interact, they form strong hydrogen bonds.
Surface tension is another property of liquids that results
from cohesion. The strong attraction (cohesion) of
particles at the surface of the liquid creates a surface
“film” that makes moving an object through the surface
of a liquid more difficult than moving the object when it
is completely submerged in the liquid. Surface tension is
also the reason liquids tend to keep a low surface area.
For example, water droplets will tend to form into a
sphere rather than spreading out flat.
Conversely, adhesion is the force of attraction between
unlike molecules. It’s the force that causes water
molecules to stick to the inside of a glass. The forces of
capillary action are strong enough to move the liquid
upward against the force of gravity.
All plants need water to survive, and most plants get that
water from the soil. Capillary action helps to move water,
and the nutrients dissolved in the water, up into the
plant’s roots and through all parts of the plant. The water
is attracted to the plant’s roots as a result of adhesion.
It then moves across the root cells to a certain type of
plant tissue called xylem. Xylem is a complex plant tissue
made up of vessels (or small hollow tubes) that transport
water and dissolved minerals through the plant. Xylem
also provides structural support to the plant.
The attraction of the water molecules to the xylem causes
the water to adhere to the sides of these tiny tubes,
climbing up the sides as more water molecules move
toward the tissue. The water, however, does not just move
upward along the sides of the xylem. It moves up through
the entire tube. The surface tension of the water keeps the
surface intact, so the whole liquid surface is dragged
upward. Cohesion then causes the rest of the water
molecules below the surface to be pulled upward as well.
In this experiment, the adhesive and cohesive forces pull
the water up into the carnation against the force of
gravity. This action can be seen by using food coloring.
The food coloring is drawn upward into the plant and its
petals with the water.
CONNECT TO THE YOU BE THE
CHEMIST CHALLENGE
For additional background information, please
review CEF’s Challenge study materials online at
http://www.chemed.org/ybtc/challenge/study.aspx.
• Additional information on states and properties of
matter, including surface tension, can be found in
the Classification of Matter section of CEF’s
Passport to Science Exploration: The Core of
Chemistry.
• Additional information on polar substances can be
found in the Chemicals by Volume—Solutions
section of CEF’s Passport to Science Exploration:
Chemistry Connections.
You Be The Chemist® Activity Guide | page 307
LESSON 25: Capillary Carnations
EXPERIMENTATION
As the students perform the experiment, challenge them to identify the independent, dependent, and controlled variables,
as well as whether there is a control setup for the experiment. (Hint: If you change the color of the water, will the color
of the petals change?) Review the information in the Scientific Inquiry section on pages 14–16 to discuss variables.
EXPERIMENTAL PROCEDURE
1. Fill a cup halfway with water and add 20–30
drops of food coloring.
2. Cut two inches off the bottom of each carnation
stem. Then, place the carnations’ stems in the
colored water.
3. Wait several hours or even until the next day to
observe the results.
4. To dye one carnation’s petals two different colors,
use a knife or scissors to split the stem lengthwise
into two pieces. Do not split the entire stem; stop
about 2–3 inches from the top of the stem.
5. Place the separated sections of the stem in different
colored water solutions, and wait several hours or
even until the next day to observe the results.
Always be careful when using scissors and
other sharp objects. When splitting the
carnations’ stems in half, it is best to do this for the
students.
DATA COLLECTION
Have students record data in their science notebooks or on
the following activity sheet. How do plants move water
from the soil into all parts of the plant? How quickly does
the water move through the plant? You can use the table in
the activity sheet (or a similar one of your own) for
students to record their data.
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LESSON 25: Capillary Carnations
ANALYSIS & CONCLUSION
Use the questions from the activity sheet or your own
questions to discuss the experimental data. Ask students
to determine whether they should accept or reject their
hypotheses. Review the information in the Scientific
Inquiry section on pages 14–16 to discuss valid and
invalid hypotheses.
ASSESSMENT/GOALS
Upon completion of this lesson, students should be able
to …
• Apply a scientific inquiry process and perform an
experiment.
• Differentiate between the different states of matter.
• Describe capillary action and the attractive forces of
cohesion, adhesion, and surface tension.
• Explain the importance of capillary action in nature.
• Differentiate between polar and nonpolar substances
and describe why water is classified as a polar
substance (see Differentiation in the Classroom).
• Explain the purpose of xylem in plants
(see Differentiation in the Classroom).
MODIFICATIONS/EXTENSIONS
• After the experiment, cut the stems of the carnations
and have the students observe the tiny tubes in the
plant. Magnifying glasses may help them to see the
tubes.
REAL-WORLD APPLICATIONS
• Most plants get the water they need to survive through
their roots. While some plants can absorb water
through their leaves, water from the ground generally
contains other nutrients that are useful to the plant.
By obtaining water from the ground, the minerals and
nutrients dissolved in the groundwater are pulled up
into the plant as well. As a result, it is important to
water the ground where plants grow. If you only water
the leaves or top of the plant, the plant will not get
enough water to survive.
• Blood is mostly water, so the forces of adhesion,
cohesion, and surface tension, and therefore capillary
action, can be observed in blood. If you prick your
finger, the blood will form droplets. Likewise, if the
edge of a sterile gauze pad touches the blood, the blood
will quickly move up through the fibers of the gauze.
COMMUNICATION
Discuss the results as a class and review the activity sheet.
Review the information in the Scientific Inquiry section on
pages 14–16 to discuss the importance of communication
to scientific progress.
Modifications and extensions provide alternative methods
for performing the lesson or similar lessons. They also
introduce ways to expand on the content topics presented
and think beyond those topics. Use the following
examples, or have a discussion to generate other ideas as
a class.
• Before the experiment, take a paper towel and hold the
bottom of it in a cup of water. Have the students watch
as water rises up the paper towel. Ask your students if
they know how this is possible. Discuss how water can
rise up against the force of gravity. Most will know
that the water is being absorbed by the paper towel,
but they may not know that it is because of capillary
action. The water adheres to the fibers in the paper
towel and climbs up the paper towel, pulling other
water molecules upward as well because of cohesion.
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LESSON 25 ACTIVITY SHEET: Capillary Carnations
OBSERVE & RESEARCH
1. Write down the materials you observe. ________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
2. Predict how these materials may be used. ______________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
3. Define the following key terms. Then, provide an example of each by writing the example or drawing/pasting an
image of the example.
Term
Definition
Example (write or add image)
Solid
Liquid
Gas
Capillary action
Cohesion
Surface tension
Adhesion
4. Consider what will occur if white carnations are placed in colored water and why.
uWrite your hypothesis. ______________________________________________________________
______________________________________________________________________________________
______________________________________________________________________________________
You Be The Chemist® Activity Guide | page 310
LESSON 25 ACTIVITY SHEET: Capillary Carnations
PERFORM YOUR EXPERIMENT
1. Fill a cup halfway with water. Add 20–30 drops of food coloring to the cup of water.
2. Use scissors to cut two inches off the bottoms of the stems. Then, place the carnations’ stems in the colored water.
3. Wait several hours or until the next day. Observe the results.
4. Try dyeing one carnation different colors. Your teacher will provide a carnation with the stem split lengthwise in two
pieces. Place the separated parts of the stem in different colored water solutions. Wait several hours or until the next
day. Observe the results.
Always be careful when using scissors and other sharp objects.
ANALYZE & CONCLUDE
1. Record your observations of the carnations’ appearance in the table below. Record the day and time of your
observation. For example, Monday, 10:00 a.m.
Day and Time
Observations
(color, healthy/wilted, etc.)
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LESSON 25 ACTIVITY SHEET: Capillary Carnations
2. What does the carnation look like before it is placed in the colored water?
__________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
3. Describe the carnation after it has been in the colored water for a few hours.
________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
4. What do you think caused the change? ____________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
5. What forces do you think are causing this to occur?
____________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
6. After you split the stem of a carnation, what do you see?
________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
7. Is your hypothesis valid? Why or why not? If not, what would be your next steps? ____________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
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LESSON 25 ACTIVITY SHEET: Capillary Carnations
EXPAND YOUR KNOWLEDGE—ADVANCED
1. Define the following key terms. Then, provide an example of each by writing the example or drawing/pasting an
image of the example.
Term
Definition
Example (write or add image)
Polar substance
Nonpolar substance
Xylem
2. When you water a plant, why would you soak the soil around the plant instead of sprinkling water on the plant’s
leaves? ____________________________________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
3. The water absorbed by plant roots is used in a process by which plants make their own food. What is this process
called? Write the chemical equation for the reaction. Where does this process take place within the plant?
______________________________________________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
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LESSON 25 ACTIVITY SHEET: Capillary Carnations
ANSWER KEY: Below are suggested answers. Other answers may also be acceptable.
OBSERVE & RESEARCH
White carnations, plastic cups, water, food coloring, scissors …
1. Write down the materials you observe. ________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
White carnations may be used as decorations. Plastic cups may be used to hold a liquid.
2. Predict how these materials may be used. ______________________________________________________________
Water may be used to drink or feed plants. Food coloring may be used to dye a substance. These materials may be used to change the color
______________________________________________________________________________________________________
of white carnations and demonstrate capillary action.
______________________________________________________________________________________________________
3. Define the following key terms. Then, provide an example of each by writing the example or drawing/pasting an
image of the example.
Term
Definition
Solid
A state of matter characterized by a definite volume
and definite shape.
Liquid
A state of matter that has a definite volume but no
definite shape; a liquid will take the shape of the
container that holds it, filling the bottom first.
Gas
A state of matter that has no definite volume or
shape; a gas will take the shape of the container
that holds it, filling the entire container
Capillary action
The ability of a substance to be drawn (possibly
upward) through a tiny tube or vessel due to
adhesive and cohesive forces; also known as
capillarity.
Cohesion
An attractive force that holds atoms or ions of a
single body together; an attraction between
particles of the same kind.
Surface tension
A property of liquids that describes the attraction of
liquid particles at the surface; the strong attraction
of particles at the surface of a liquid creates a
surface “film."
Adhesion
An attractive force that holds atoms or ions of
different substances together.
Example (write or add image)
4. Consider what will occur if white carnations are placed in colored water and why.
White carnation petals will turn the color of the dyed water because of capillary
uWrite your hypothesis. ______________________________________________________________
action within the plant.
______________________________________________________________________________________
______________________________________________________________________________________
You Be The Chemist® Activity Guide | page 314
LESSON 25 ACTIVITY SHEET: Capillary Carnations
ANSWER KEY: Below are suggested answers. Other answers may also be acceptable.
PERFORM YOUR EXPERIMENT
1. Fill a cup halfway with water. Add 20–30 drops of food coloring to the cup of water.
2. Use scissors to cut two inches off the bottoms of the stems. Then, place the carnations’ stems in the colored water.
3. Wait several hours or until the next day. Observe the results.
4. Try dyeing one carnation different colors. Your teacher will provide a carnation with the stem split lengthwise in two
pieces. Place the separated parts of the stem in different colored water solutions. Wait several hours or until the next
day. Observe the results.
Always be careful when using scissors and other sharp objects.
ANALYZE & CONCLUDE
1. Record your observations of the carnations’ appearance in the table below. Record the day and time of your
observation. For example, Monday, 10:00 a.m.
Day and Time
Observations
(color, healthy/wilted, etc.)
Answers will vary
Answers will vary
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LESSON 25 ACTIVITY SHEET: Capillary Carnations
ANSWER KEY: Below are suggested answers. Other answers may also be acceptable.
2. What does the carnation look like before it is placed in the colored water?
The carnation looks healthy. It is upright in the
__________________________________
cup, and the petals are white.
______________________________________________________________________________________________________
______________________________________________________________________________________________________
3. Describe the carnation after it has been in the colored water for a few hours.
The bottoms of the petals begin to show
________________________________
the color of the water.
______________________________________________________________________________________________________
______________________________________________________________________________________________________
Capillary action drew the colored water up into the carnation, which dyed the petals.
4. What do you think caused the change? ____________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
5. What forces do you think are causing this to occur?
The forces of cohesion and adhesion cause the capillary action to occur.
____________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
6. After you split the stem of a carnation, what do you see?
The inside of the carnation stem shows tiny strands of color.
________________________________________________
These strands of color are the xylem that are transporting the colored water through the plant.
______________________________________________________________________________________________________
______________________________________________________________________________________________________
7. Is your hypothesis valid? Why or why not? If not, what would be your next steps? ____________________________
Answer 1: Valid because the data support my hypothesis.
______________________________________________________________________________________________________
Answer 2: Invalid because the data do not support my hypothesis. I would reject my hypothesis and could form a new one, such as …
______________________________________________________________________________________________________
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LESSON 25 ACTIVITY SHEET: Capillary Carnations
ANSWER KEY: Below are suggested answers. Other answers may also be acceptable.
EXPAND YOUR KNOWLEDGE—ADVANCED
Have students complete this section if you used the advanced differentiation information, or challenge them to find the answers to these
questions at home and discuss how these terms relate to the experiment in class the next day.
1. Define the following key terms. Then, provide an example of each by writing the example or drawing/pasting an
image of the example.
Term
Definition
Polar substance
A substance made up of particles that have an uneven
distribution of electrons, creating a negative and a positive
side.
Nonpolar substance
A substance made up of particles that have an even
distribution of electrons; the charges on these molecules
are neutralized.
Xylem
A complex plant tissue made up of networks of vessels (or
small hollow tubes) that transport water and dissolved
minerals through the plant; provides structural support to
the plant.
Example (write or add image)
2. When you water a plant, why would you soak the soil around the plant instead of sprinkling water on the plant’s
You soak the soil around the plant with water because plants absorb water through their roots, which are in the ground. The water is
leaves? ____________________________________________________________________________________________
then transported throughout the plant by tiny vessels. If you just sprinkled the water on the plants leaves, the plant may not absorb enough
______________________________________________________________________________________________________
water to survive.
______________________________________________________________________________________________________
3. The water absorbed by plant roots is used in a process by which plants make their own food. What is this process
called? Write the chemical equation for the reaction. Where does this process take place within the plant?
Photosynthesis is the process by which plants make their own food. The chemical equation for the reaction is
______________________________________________________________________________________________________
6CO2 + 6H2O + sunlight (energy) g C6H12O6 + 6O2. The process occurs within the chloroplasts found in the plant cells.
______________________________________________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
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