How Fast Do Different Liquids
Flow?
Today, we will be investigating liquids and how they flow. You
will each have a recording sheet for your predictions,
observations and results. For each liquid we test, you will first
record how far you think the liquid will move by drawing the
distance and labeling it #1. After observing the eyedropper of
liquid at the top of the board and the flow of the liquid, you will
record your observation of how it really flowed and label it with
a #2. Try to include a word that describes how the liquid
moved, such as "fast," "slow," "drip," "stuck," "no flow."
Later in the week, we will use these data to create a graph of
the liquids that were investigated. The graph will show the
liquids in order from the slowest to fastest flow rate.
How Fast Do Different Liquids Flow?
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How Fast Do Different Liquids Flow?
Suggested Grade Span
K–2
Task
Today, we will be investigating liquids and how they flow. You will each have a recording sheet
for your predictions, observations and results. For each liquid we test, you will first record how
far you think the liquid will move by drawing the distance and labeling it #1. After observing the
eyedropper of liquid at the top of the board and the flow of the liquid, you will record your
observation of how it really flowed and label it with a #2. Try to include a word that describes
how the liquid moved, such as "fast," "slow," "drip," "stuck," "no flow."
Later in the week, we will use these data to create a graph of the liquids that were investigated.
The graph will show the liquids in order from the slowest to fastest flow rate.
Big Ideas and Unifying Concepts
Cause and effect
Change and constancy
Physical Science Concept
Properties of matter
Mathematics Concepts
Comparison of attributes or effects
Data collection, organization and analysis
Graphs, tables and representations
Measurement
Time Required for the Task
Approximately 45 minutes.
Context
This scientific investigation introduced a comparison of the characteristics of a variety of liquids
during a study of matter with first graders. The children had previously participated in
investigations with liquids, such as observing the action of carbon dioxide working with ginger
How Fast Do Different Liquids Flow?
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ale and raisins. Chemical reactions were investigated by simulating volcanic eruptions using
baking soda, water, vinegar, dish soap and food coloring. Capillary action was also investigated
using a variety of paper-related products with our “big partners” (fifth graders).
All of these investigations provided experiences with a variety of solids and liquids, especially
water. Then I introduced a new scientific concept: viscosity. This involves measuring how fast a
liquid flows.
What the Task Accomplishes
This investigation was originally done with my first graders as “ Thick or Thin?” The purpose of
the investigation was to compare the viscosity of different liquids that were largely familiar to the
students. By using liquids that were familiar, the students could tap into their prior knowledge
and make connections to their daily lives. They observed, predicted and compared how long it
took each of the liquids to move down a wipe-off board, tilted with a wooden block about 2
inches high. This took approximately two minutes. From trial and error with my students, we
discovered that the small tilt was not sufficient in comparing or achieving accurate results.
This provided an excellent class discussion about how variables can change/affect the scientific
results of an experiment. As an extension, we decided to tilt the board about four inches and
redesigned our investigation of the liquids again.
How the Student Will Investigate
This was one of those rare investigations that I facilitated instead of having the children pair off,
as usual, to do the activity. I feel this is appropriate to do sometimes; it allowed me to observe
everyone, engage in dialogue frequently, watch recording procedures and closely monitor those
who might need more assistance during the investigation. It also gave me a chance to discuss
“fair testing,” as I kept the slant of the board and the amount of liquid from eyedroppers
constant for each trial.
I did this investigation in a whole group with the students on the rug in a circle. Each child had a
clipboard for his/her recording sheet. Throughout the activity, we discussed their predictions,
observations and recording of results. I used a wipe-off board tilted with a wooden block and
had an eyedropper for each liquid. Part of the reason for this demonstration approach was the
very messy nature of the liquids and not having a large quantity of eyedroppers. This could be
set up in cooperative groups of four, if you had a supply of eyedroppers (25) so that at least
three to five liquids could be investigated by each cooperative group.
Students were given the choice of the sequence of liquids they wanted to observe and test.
Even with this change in scientific presentation, it was still very inquiry based, and students
were very animated and engaged during this investigation. On each student’s recording sheet,
s/he was asked to record how far s/he thought the liquid would move by drawing the distance
and labeling it with a #1. After observing the eyedropper of liquid at the top of the board and the
flow of the liquid, each student was asked to record his/her observation and label it with a #2.
The students were also encouraged to include a word that described the movement of the
How Fast Do Different Liquids Flow?
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liquid, such as "fast," "slow," "drip," "stuck," "no flow". There were a total of eight different liquids
that were predicted, observed and recorded for their viscosity. Later in the week, the students
were asked to review their data and create a graph of the liquids that were investigated. The
graph needed to reflect a sequence from the slowest to fastest flow rate of the liquids tested.
Interdisciplinary Links and Extensions
Science
Students could use timers and tape measures to measure the actual distance each liquid goes
in the same amount of time or measure the amount of time to go the same distances. Two
excellent sources that provided ideas for activities about matter were Super Science
Concoctions, by Jill Frankel Hauser, and Janice VanCleave’s 203 Icy, Freezing, Frosty, Cool &
Wild Experiments. Investigate absorption using raisins, seeds or gummi bears with a liquid in
clear cups. Observe and check the cups, recording observations every hour for six hours.
Another investigation could involve examining solutions by adding different particles of solids
into liquids, such as salt, sugar, cornmeal, flour, rice. An activity that could explore the
differences in the forming of ice crystals could begin with the question: Why are homemade
Popsicles softer than ice? Students could investigate how the density of different liquids varies
by layering water, cooking oil and corn syrup in a clear cup. There are other liquids that can be
layered to extend this investigation.
Social Studies
Extensions could also be made to an environmental study of how oil spills affect our oceans
and how critical cleanup operations are for ecosystems. Investigate the jobs needed to run
sewage treatment plants. Have children investigate why these operations are important to our
water supplies. Read Water, Water! by Tom Johnston, which demonstrates the many uses of
water, where it comes from, how it is wasted and why it is vital to the survival of living things.
Literacy
I always introduce scientific investigations through a variety of literature with my first graders.
Some of the books that I use are Water, by Frank Ash; The Way of the Willow Branch, by
Emery and Durga Bernhard; Earth Verses and Water Rhymes, by J. Patrick Lewis; The Lost
Lake, by Allen Say; Rain, Rain Rivers, by Uri Shulevitz; and To Climb a Waterfall, by Jean
Craighead George. Many of these books illustrate the water cycle, encourage healthy attitudes
for taking care of water supplies and investigate pollution problems. To Climb a Waterfall
inspires artistic connections through the illustrations of Thomas Locker.
Art/Music/Movement
Children love to move their bodies to music, which can be integrated in a meaningful way to
extend understanding of science concepts. Ask children to demonstrate the water cycle,
independently or in cooperative groups. Create posters to show “water problems” and how to
protect different water ecosystems. Model writing poetry with children, using different
experiences they have had with water. Illustrate how amphibians, mammals, reptiles and birds
utilize water. Use Voices of the Wild, by Jonathan London, to inspire poetry and art projects.
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Mathematics
Activities could be connected to the task comparing the measurement of volume using liquids
and solids. How many teaspoons compared with tablespoons does it take to fill a certain size
container? Mix different colored liquids using eyedroppers, and have children count and record
the drops needed to make different colors. Make “oobleck” and have the children determine the
criteria to answer the question: Does it act more like a solid or a liquid? Compare the weights of
a variety of liquids, and graph the results while controlling the type of counters used for balance.
Teaching Tips and Guiding Questions
A constructivist science teacher is always modeling and asking questions to guide the thinking
process of students to the big ideas. Questions that might guide and engage children’s thinking
during the investigation and connected extensions include:
• What do you notice about the liquid in the container?
• How does the liquid act coming from the eyedropper?
• How far do you think this liquid will travel compared to the previous one? Why do you think
that?
• How is this liquid like another one you have seen at home?
• Do all the materials flow in the same way? Why do you think that?
• Can you describe other liquids that will act in the same way, based on your observations?
• What is an advantage in packaging soup in cans or packages?
• What do you think the expression “like water off a duck’s back” means?
• How does a sea otter’s fur act like the feathers of a duck? Do we have clothing that does
the same thing for us?
• What predictions would you make about the rate of flow of water through different kinds of
soils (loam, clay and sand)? Can you make a test to help you find out?
• How would you compare the flow of pine pitch to the flow of sap in a maple tree if both
were tapped?
• Would the same liquid reach the bottom first in repeated trials? Why or why not? How
many trials should be repeated in order to verify your results?
• How do you think cold or heat affects the flow (viscosity) of a liquid? How could you test
your theory?
Concepts to be Assessed
(Unifying concepts/big ideas and science concepts to be assessed using the Science
Exemplars Rubric under the criterion: Science Concepts and Related Content)
Physical Science – Properties of Matter: Students observe the physical properties of matter
and sort according to similarities and differences. Students understand the term viscosity.
Students understand that viscosity is a physical property of liquids and that the more viscous a
liquid, the slower it flows. Students compare / contrast liquids by observing patterns of how
liquids behave.
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Scientific Method: Students begin to understand the effects of external conditions that cause
observed changes in results. Students determine the patterns by making a graph or table of
measurements (change and constancy). Students observe and explain reactions when
variables are controlled. Students understand that the most viscous liquid will reach the bottom
of the ramp last, unless there is experimental error. Students use observations to make
predictions and classify materials (cause and effect).
Mathematics: Students use number sense, counting, graphing, probability and numerical
data/precise measurements to describe events, answer questions and provide evidence for
scientific explanations. Students compare attributes or effects.
Skills to be Developed
(Science process skills to be assessed using the Science Exemplars Rubric under the criteria:
Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)
Scientific Method: Observing, predicting, hypothesizing, collecting and recording data,
manipulation of tools, drawing conclusions, communicating findings and raising new questions.
Other Science Standards and Concepts Addressed
Scientific Method: Students describe, predict, investigate and explain phenomena. Students
control variables.
Scientific Theory: Students look for evidence that explains why things happen and modify
explanations when new observations are made.
Physical Science – Properties of Matter: Students describe and sort objects and materials
according to observations of similarities and differences of physical properties.
Communication: Students use verbal and nonverbal skills to express themselves effectively.
Students interpret and communicate and use mathematical, scientific and technological
notation and representation.
Mathematics: Students use reasoning and create a variety of strategies/approaches to solve
problems. Students apply mathematics to solve complex scientific and technological problems.
Suggested Materials
I brought in a variety of familiar liquids for the students to investigate viscosity. I included
cooking oil, salad dressing (French), colored water, honey, tomato soup (from a can), shampoo,
seltzer and sunscreen gel. Other liquid-based materials that could be investigated are corn
syrup, molasses, chocolate milk, baby oil, hand lotion and a different consistency of soups and
dressings. I used a separate eyedropper for each substance, a wipe-off board that was
approximately 8 1/2 inch by 11 inch, a block of wood to support the ramp, a wipeoff pen for
labeling and a plastic mat at the end of the board to catch each liquid.
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Each student needs a recording sheet that has the outline of a board for each liquid to be
observed. I used four on each side, leaving room for drawing and labeling.
Possible Solutions
As the children make more observations of the liquids presented and apply their prior
knowledge, they should begin to make closer predictions based on the observed thickness of
each liquid. Viscosity is a measure of how a liquid flows. Based on their data, the children
should be able to make a chart or graph to represent the levels of viscosity in a clear sequence,
going from the fastest flow rate to the slowest flow rate or the reverse.
The liquids with the least viscosity will have the fastest flow rates. Each child’s “Thick or Thin?”
prediction/results sheet was used to build skills in observation and prediction. The final graphing
sequence was used for the scientific assessment. The sequence should reflect suntan gel or
honey, tomato soup, shampoo, salad dressing or cooking oil, water and seltzer.
After investigating, I set the different liquids in their original containers on a table in a mixed
sequence for the children to see again while they were constructing their graphs. This allowed
them to change their minds as they reviewed and reconstructed information from their
observations in order to better match the true viscosity of the liquids.
Task-Specific Assessment Notes
Novice
This student records each liquid; however, s/he does not use prior knowledge on the “Thick or
Thin?” recording sheet for most of the liquids that were tested. The thicker liquids are predicted
to move faster, which means scientific reasoning is not used during observations of the liquids
in their containers or during the demonstrations on the tilted board. The graph shows no
organization or understanding of the concept of viscosity.
Apprentice
This student completes the task, recording most of the required data on the “Thick or Thin?”
sheet, and demonstrates scientific reasoning and the use of prior knowledge in predicting the
viscosity of the liquids. The graph is organized but does not reflect a correct sequence for some
of the liquids. This student makes an attempt to use his/her scientific observations and data to
support the graph.
Practitioner
This student’s solution is detailed and complete, and prior knowledge is used in predicting the
viscosity of the liquids. The “Thick or Thin?” recording sheet reflects strong scientific reasoning
and accuracy in recording the predictions and results. The final graph results are accurate for
the liquids that were observed and sequenced by the student.
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Expert
This student’s solution is complete and detailed in describing the flow of the liquids that were
tested. The predictions become closer as the investigation progresses, and there is evidence of
prior knowledge shown throughout the recorded results. The student demonstrates extended
thinking by indicating the fast droplets seen with the colored water, which was different from the
fast stream of seltzer that flowed down the wipeoff board. The graph indicates a clear sequence
of liquids that shows the rate of flow from the slowest to the fastest.
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Novice
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Novice
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Novice
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Apprentice
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Apprentice
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Apprentice
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Practitioner
How Fast Do Different Liquids Flow?
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Practitioner
How Fast Do Different Liquids Flow?
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Practitioner
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Expert
How Fast Do Different Liquids Flow?
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Expert
How Fast Do Different Liquids Flow?
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Expert
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