how and why does water climb?info.ritenour.k12.mo.us/rsd/science_exemplars/k_5/pdfs/task262.pdf ·...

How and Why Does Water Climb?

Did you ever wonder about how water gets up into the stemand leaves of a plant? Have you ever noticed how a papertowel or clothing soaks up water? Did you know that water candefy gravity by pulling itself upward? This special event iscalled capillary action. How far do you think water will climb?Let’s test different kinds of paper to watch it moving and to findout which material will allow water to climb the highest. We willuse colored water, so we can observe it more closely, andrecord our observations on a recording sheet. Don’t forget tomeasure how far the water travels each time.

1 of 14How and Why Does Water Climb?

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How and Why Does Water Climb?

Suggested Grade Span

K–2

Task

Did you ever wonder about how water gets up into the stem and leaves of a plant? Have youever noticed how a paper towel or clothing soaks up water? Did you know that water can defygravity by pulling itself upward? This special event is called capillary action. How far do youthink water will climb? Let’s test different kinds of paper to watch it moving and to find out whichmaterial will allow water to climb the highest. We will use colored water, so we can observe itmore closely, and record our observations on a recording sheet. Don’t forget to measure howfar the water travels each time.

Big Ideas and Unifying Concepts

Cause and effectModelsSystems

Physical Science Concepts

Motion and forcesProperties of matter

Mathematics Concepts

Data collection, organization and analysisMeasurementNumber properties, numeration and number sense

Time Required for the Task

Approximately 45–60 minutes (over 2 days):

Day 1: Exploration of capillary action

Day 2: Investigation and recording of observations and results



Context

This investigation is an extension of a previous water activity (and larger unit of study) thatinvolved the observation of surface tension. (See "What Do We Know About Water?") Studentsuse their prior knowledge from that and other activities to extend their conceptual understandingfor this inquiry.

What the Task Accomplishes

This task combines the skills needed for measuring, recording, and organizing data to makecomparisons with observation skills. The more students practice these skills, the greatersuccess and confidence they will experience. This has promoted a positive attitude towardscience in my classroom and in the homes of many of my students, where investigations oftencontinue.

How the Student Will Investigate

On the first day, after observing that students were having difficulty controlling the variables -such as folding the paper, adding the water, and observing the absorption (timing andmeasuring) - I moved from group to group guiding them in developing techniques for using thematerials consistently. As a class, we decided to fold the paper the “long way” and to use theclassroom clock’s red second hand to time the samples of paper in the colored water, each forone minute. We also talked about putting the same amount of water on the paper to make it a“fair test.”

On the second day, groups of students were given a recording sheet and asked to test fivetypes of paper and to record results. Each type of paper was to be labeled. The height thewater moved up the paper was measured and recorded after one minute, and a drawing wasmade to show the results. Although each student completed an individual recording sheet, jobswere assigned and rotated for each sample: (1) timer, (2) measurer, (3) label checker and (4)drawing checker. (These jobs could also remain the same throughout the testing. An easy wayto facilitate task assignments is to give each student in the group a number (1 - 4) anddesignate job tasks for each number.)

Interdisciplinary Links and Extensions

ScienceOther related capillary action activities could include timing water races on different types ofstrings, observing celery stalks in colored water, comparing absorption rates for a plant with andwithout root hairs attached to the main root, and/or product testing of different brands of papertowels or sponges. Cross sections of plant stems could be examined to see the path the watertakes to the leaves.

Students could discuss why blood vessels are called capillaries and how blood moving thoughthe body is like water moving though plants or soils.



Social StudiesLearning about water systems designed by humans, for purposes such as irrigation andfiltration, artesian wells or aqueducts, might provide interesting comparisons to natural systemsand how gravity plays a part.

Language ArtsSome of the children’s literature I used for this unit were: Let’s Look at Rain, by JacquelineDineen; Water, by Webb & Fairclough; The Magic School Bus Wet All Over and A River RanWild, by Lynn Cherry. These books illustrated the water cycle, the importance of rain for plantsand different habitats, the history of a Native American Indian culture on a river, and gravityexperiments with water.

Movement/MusicMy students enjoy water songs, rounds and raps, using such songs as“The Dirty Water Blues”and “Evergreen Everblue.”

MathematicsThroughout our unit on water, I asked my students to keep logs (counting and measuring)tracking the use of water at home and in school. We include minutes in the shower, numbers offlushes and glasses of water consumed to talk about water conservation strategies. We alsocreate original story problems to solve. (If five people are in the family and each person drinkstwo glasses of water. . . or, If a large dog drinks three gallons of water a day. . .) Students canresearch, graph and compare how much water different animals require daily.

Teaching Tips and Guiding Questions

I have found that my students are much more successful when I allow for free exploration incooperative groups at least one day before I ask them to record data for any given inquiry. Thisapproach also encourages them to draw on their prior knowledge to formulate predictions andchallenge misconceptions. For students who have not had many rich, multisensoryexperiences, this also gives them opportunities to build a solid base of conceptualunderstanding. I try to promote “thinking out loud” by asking questions like:

• How do you think we should fold the paper? Time the results? How can we be sure thateach test uses the same amount of water?

• What differences (texture, the weave, feel, etc.) do you see in the papers?• Did the colored water travel at the same or at different rates?• Can you demonstrate to me how you measured your paper?• Which paper would be best for cleaning up spills? Why do you say so?• Did any of the papers do something you did not expect it to do?• Why do you think this paper (coffee filter, wax paper, paper towel, etc.) is the kind of paper

used for this specific purpose?• Did you notice anything about water that reminds you of something we have already done

with water investigations?• Why do you think the roots of plants have different shapes, sizes and textures?



Concepts to be Assessed

(Unifying concepts/big ideas and science concepts to be assessed using the ExemplarsScience Rubric under the criterion: Science Concepts and Related Content)

Physical Science – Properties of Matter: Students explore, observe and describe physicalproperties and characteristics of water and liquids (capillary action - ability to climb up a surfaceagainst the pull of gravity; absorption - water molecules “sticking” to other substances; cohesion- water molecules “sticking” to each other).

Scientific Method: Students observe and explain reactions when variables are controlled anddescribe cause-effect relationships with some justification, using data and prior knowledge(cause and effect). Students see that how a model works after changes are made to it maysuggest how the real thing would work if the same thing were done to it (models).

Mathematics: Students use timing, counting and measuring to describe events, answerquestions and provide evidence for scientific explanations.

Skills to be Developed

(Science process skills to be assessed using the Exemplars Science Rubric under the criteria:Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)

Scientific Method: Observing, predicting, hypothesizing, collecting and recording data,manipulating tools, controlling variables, drawing conclusions, communicating findings andraising new questions.

Other Science Stamdards and Concepts Addressed

Scientific Method: Students describe, predict, investigate and explain phenomena. Studentscontrol variables.

Scientific Theory: Students look for evidence that explains why things happen and modifyexplanations when new observations are made.

Physical Science – Properties of Matter: Students observe, describe and sort objects andmaterials according to observations of similarities and differences of physical properties.

Physical Science – Motion and Forces: Students can explain that everything on or near theearth that is pulled toward the earth’s center by gravitational force.

Mathematics: Students use number sense, counting, and grouping numbers; understand andapply concepts of more than/less than; and use numerical data and (precise) measurements indescribing events, answering questions, providing evidence for scientific explanations andchallenging misconceptions.



Suggested Materials

For paper samples, I provided store-brand paper towels, wax paper, coffee filters, brown(school) paper towels, white drawing paper, newsprint, computer paper and coloredconstruction paper. Students selected five to test and were encouraged to try others they couldfind in the room. (Some tried playing cards, old bookmarkers and different-colored paper.) Eachgroup placed the cups of colored water in a clear plastic tub. I added green food coloring to thewater ahead of time. Magnifying lenses and math manipulatives were available as needed forexamining and measuring. Each student had a recording sheet to complete.

Possible Solutions

Student drawings, recordings and explanations should demonstrate understanding of theconcepts of cohesion, absorption and capillary action, although I did not expect students to usethe scientific terms. A minimum of five papers should be recorded, labeled, drawn andmeasured. Students should measure accurately to the nearest half inch (of object used) andidentify that papers such as paper towels and coffee filters absorb more water than wax paper,etc. Differing rates of absorption should also be noted, and some observations about thediffering textures or weaves of the papers might be described.

Task-Specific Assessment Notes

NoviceThis student’s solution is complete but lacking in necessary details. The drawings are notaccurate (for example, there should be water drops running off the wax paper, the tip of thecoffee filter should be wet, and the white drawing paper and brown paper look exactly the samebut have different measurements). There is some evidence of understanding how to use toolsand record data.

ApprenticeThis student’s solution is labeled and more than five items are tested. The measurement forwax paper is missing, and some of the drawings are unclear or inconsistent with measurements(e.g., the cup says “0” for the measure, yet the drawing shows water absorption). There isevidence that the student collected data, but additional observations are noted for only threepapers (e.g., “slid of” for wax paper). The student did not clearly identify which paper allowedthe water to climb the highest.

PractitionerThis student’s solutions are complete. All data are recorded accurately; labels are clear anddrawings are vivid, showing how water beads up on the wax paper. The student has includedthe rate of capillary action for the one minute that was observed (fast/slow notations). Thestudent tests additional items (playing card, sorting cup, etc.), as well. Conclusions are drawnfrom data collected – evidence of conceptual understanding and reasoning.



ExpertThis student’s solutions are complete and detailed. The drawings are clearly labeled, andadditional detailed observations are noted for most of the items tested. Conclusions are drawnfrom data collected and include a comparison of the two fastest materials – evidence ofconceptual understanding and reasoning.



Novice



Apprentice



Practitioner



Expert



how and why does water climb?info.ritenour.k12.mo.us/rsd/science_exemplars/k_5/pdfs/task262.pdf ·...

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