Which Liquid Is Heaviest?
In this investigation, you will be given 4 liquids: shampoo
(green), glue (white), oil (yellow) and water. After we make
some predictions, you will do some testing and make
observations to find out which liquid is the heaviest and which
is the lightest. Remember to pour your liquid very slowly, along
the side of the container, when you add each one. Then
observe what happens before pouring the next liquid in.
When you are done with your tests, draw a picture to show
each of the liquids. Then, be sure to record what you learned
about which liquid is heaviest and which is lightest.
Which Liquid Is Heaviest?
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Which Liquid Is Heaviest?
Suggested Grade Span
K–2
Task
In this investigation, you will be given 4 liquids: shampoo (green), glue (white), oil (yellow) and
water. After we make some predictions, you will do some testing and make observations to find
out which liquid is the heaviest and which is the lightest. Remember to pour your liquid very
slowly, along the side of the container, when you add each one. Then observe what happens
before pouring the next liquid in.
When you are done with your tests, draw a picture to show each of the liquids. Then, be sure to
record what you learned about which liquid is heaviest and which is lightest.
Big Ideas and Unifying Concepts
Cause and effect
Form and function
Physical Science Concept
Properties of matter
Mathematics Concepts
Data collection, organization and analysis
Diagrams
Time Required for the Task
45 minutes.
Context
This task was given to students during the liquids portion of a unit on solids, liquids and gases.
Students had been exploring, observing and investigating liquids to discover some of the many
properties and characteristics of liquids. Students had also been practicing drawing and writing
about their observations and investigations. This task allowed students to practice these skills
and to learn about conducting investigations.
Which Liquid Is Heaviest?
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While the basic format for this lesson came from a commercially packaged science program,
the teacher structured it so that it was more open-ended, allowing students to make decisions
about how to investigate the question at hand. (See the "Teaching Tips and Guiding Questions"
section for some general ideas for modifying and guiding science activities and experiments.)
What the Task Accomplishes
This task is used for formative assessment purposes. It was given during an extensive unit on
solids, liquids and gases. It assesses the ability to conduct a guided investigation and to
describe the investigation and observations through drawing and writing. In this task, students
must also be able to interpret and draw conclusions about what they observed.
How the Student Will Investigate
Before beginning this investigation, the whole class reviewed what we had already learned
about liquids. The teacher then held up cups of each of the liquids and posed the question,
“Which liquid is the heaviest?” Students made predictions about which liquid was the heaviest
and which was the lightest. These predictions were recorded, tallied and put on the chart. We
then discussed how we might find out which was the heaviest.
Students’ ideas about testing the question were listed next. As a whole group, we selected the
most appropriate way to investigate this question (by layering the liquids) and the teacher
demonstrated how to gently pour one liquid into the container so that the students do not have
to wait to see where the liquids end up.
Materials were then handed out to students. Students worked in pairs and began layering the
liquids, pouring each one to observe what happens. After adding all four liquids, students
observed which was heaviest and which was lightest. Next, they drew a picture of what they
had discovered and wrote about their observations. As a whole group, we met as scientists to
discuss the results of the layering, checked our results and compared them to our earlier
predictions.
Note: If students pour quickly, the liquids try to mix first, and it takes longer for them to separate
and layer. If this happens, you may have to wait until later in the day or until the next day to see
results. Students might take a “practice pour” first into a class container to get the idea of fast
and slow pouring to layer the liquids.
Interdisciplinary Links and Extensions
Science
Try adding a “new liquid” to the existing column after making a prediction. Other investigations
to learn about the physical properties of liquids might include observing how liquids move
(viscosity), how liquids mix or mix at different temperatures (solutions, convection), how liquids
make drops, how liquids behave in different containers or at different temperatures (solid-liquidgas: changing states though freezing, melting, evaporating), how liquids are absorbed into/by
different materials, etc.
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Mathematics
Liquids can be measured and weighed. Students can learn about volume and mass during a
study of liquids; they can compare liquids though graphing results. Students can begin this
investigation by discussing fair testing, measuring amounts of each liquid and keeping the
amounts the same.
Language Arts
During the course of the unit, students kept journals about many of their observations of
different types of matter (solids, liquids and gases).
Some children’s literature about solids, liquids and gases include:
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Hot-Air Henry, by Mary Calhoun
Very Last First Time, by Jan Andrews
Water’s Way, by Lisa Westberg Peters
Supersuits, by Vicki Cobb
A Chilling Story: How Things Cool Down, by Eve Stwertka
Bartholomew and the Oobleck, by Dr. Suess
Horrible Harry and the Green Slim, by Suzy Kline
Salt, by Harve Zemach
Two Bad Ants, by Chris Van Allsburg
The Legend of the Bluebonnet, by Tomie dePaola
There’s a Hippo in My Bath, by Kyoko Matsuoka
Floating and Sinking, by Franklyn Mansfield Branley
Water Is Wet, by Sally Cartwright
Liquids, by William Lumsden
Who Sank the Boat? by Pamela Allen
Bubbles, by Bernie Zubrowski
The Lady Who Put Salt in Her Coffee, by Lucretia Hale
Teaching Tips and Guiding Questions
Layering liquids is one of the best ways to determine fairly which liquid is the heaviest and
which is the lightest. Students may need some prompting, through teacher discussion and
demonstration, to generate this idea for investigation. For showing the different liquids through
drawing, students drew the water as blue, the glue as white, the oil as yellow and the shampoo
as green.
At the first-grade level, students may still need help writing about what they observe. We
scribed for students whenever necessary.
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Some possible guiding questions to ask students as they observe are:
• What does it mean to be heavier? lighter?
• If an object is heavier (like a rock), what happens when you put it into a liquid? If an object
is lighter (like a feather), what happens?
• Which liquid do you think is the heaviest? the lightest? Why do you think so?
• What ideas do you have about investigating which liquid is heaviest? What things could
you try to find out? Which would work the best? Which would be the fairest way to find out?
• Which one will you pour first? second? third? Why did you pour them in that order?
• What do you observe when you pour the glue into the shampoo? the shampoo into the
water? the oil into the water? What happens? What are your ideas about what happened?
• What did you find out? How could you show your results? How can you tell about what you
learned?
• What ideas do you have about heavy and light liquids?
• Did anything surprise you?
Note: Often, prepackaged program activities can be modified so that they are more openended. Here are some general ideas for modifying activities and experiments:
• Give the question to the whole class. As a whole group, plan how to investigate it rather
than following the directions given. Come back as a whole group and share results and
draw conclusions together.
• Have students as a whole group brainstorm questions about the topic/concept being
studied and select by consensus one question to investigate. Plan together how to
investigate it and then have students work in small groups to investigate. Or have the small
groups plan their own investigations of the question.
• Use the materials in the kit to give students exploration and observation opportunities. Use
these materials to stimulate questions and investigations rather than doing all the activities
listed in the program.
• Create your own more generic forms for recording investigation results or have the
students create their own.
• Always allow time for students to talk about and communicate their learning with others.
Have scientist meetings and discussions frequently.
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)
Scientific Method: Students observe and explain cause-effect relationships, with some
justification, using data and prior knowledge (cause and effect).
Physical Science – Properties of Matter: Students observe materials, make predictions and
classify materials.
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Mathematics: Students use diagrams and collect, organize and analyze data appropriately.
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 through
words and writing, manipulating tools, drawing conclusions, communicating findings,
challenging misconceptions and raising new questions.
Other Science Standards and Concepts Addressed
Scientific Method: Students describe, predict, investigate and explain phenomena.
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.
Suggested Materials
The teacher provides to each student and/or pair of students:
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One (larger) clear, plastic cup to layer the liquids
Four small plastic cups with: shampoo (green), oil (yellow), glue (white) and water
Recording sheets
Pencils
Possible Solutions
A correct solution will include a labeled picture of the layers, with oil being the top layer/lightest,
then water, then shampoo, then glue as the heaviest. There should also be a written description
of the results and conclusions drawn from the results.
Task-Specific Assessment Notes
Novice
The student includes a picture of the layers, but it is difficult to see which is which because
there are no labels or lines to indicate the layering. Results are stated for three of the four
liquids. The student is correct in concluding that the glue is the heaviest and the oil the lightest,
but incorrect in concluding that water is the second heaviest.
Which Liquid Is Heaviest?
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Apprentice
The student includes a picture of the layers, and each layer is clear; however, without labels, it
is difficult to tell which layer is for which liquid. The student is correct in concluding that the glue
is the heaviest and the oil the lightest. The student does not record where the water or
shampoo is in the layers.
Practitioner
The student includes a picture of the layers, which is labeled and correct. The student correctly
states results for four liquids: that the glue is the heaviest, the soap the second heaviest, the
water third heaviest and the oil the lightest. The student makes a conclusion (so the glue was
heaviest) based on observations.
Expert
The student includes a picture of the layers, which is labeled and correct. The student correctly
states results for four liquids: that the glue is the heaviest, the soap second heaviest, the water
third heaviest and the oil the lightest. The student links conclusions to observations about how
the liquids behaved when layering (the oil floated to the top, the glue sunk to the bottom).
Which Liquid Is Heaviest?
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Novice
Which Liquid Is Heaviest?
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Apprentice
Which Liquid Is Heaviest?
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Practitioner
Which Liquid Is Heaviest?
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Expert
Which Liquid Is Heaviest?
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