Overview
Procedure
Toolbox

Anchoring Phenomenon

Sewage water is consumed by people, but they do not get sick.

Lesson Concept

Compare multiple design solutions and their merit for separating substances from a mixture.

Identified Problem

Water collected from a town may be contaminated. The town officials are requesting help to design a process that will identify the particles in the water and then clean the water.

Standards

Click here for NGSS, CCSS–ELA, and California ELD standards.

Time | Materials | Advance Preparation

Time

4 hours 35 minutes

30 minutesEngage
60 minutesExplore
Plus overnight–or longer–for evaporation
60 minutesExplain 1
45 minutesExplain 2
45 minutesElaborate
35 minutesEvaluate

Materials

Whole Class (same materials as Lesson 4: Cleaning Water)

  • Chart paper
  • Town Water Samples (from Lesson 1: Town Water Samples)
  • 20 paper bowls
  • 20 8-oz. clear plastic cups
  • 20 4-in. squares of screens
  • 20 4-in. pieces of cheesecloth
  • 20 small shallow plastic bowls
  • 2 1-quart water containers
  • 20 plastic spoons
  • 20 1-inch round magnets
  • 20 coffee filters
  • 1 paper towel roll
  • 30 hand lenses
  • 12 3-oz. small cups
  • 4 small digital kitchen scales
  • 15 tablespoons (kitchen measuring type)
  • 5.5.C1: Criteria for Observations

Group (Groups of 2)

  • 1 16-oz. plastic or paper cup
  • ⅛ cup of sand
  • ⅛ cup of salt
  • ⅛ cup of iron filings
  • 3 3-oz. cups
  • 2 tsp. sand
  • 2 tsp. salt
  • 2 tsp. iron filings
  • 2 whiteboards

Individual

Advance Preparation

  1. For each set of partners, mix ⅛ cup of each substance (sand, salt, iron filings) in the large plastic cup; add 1½ cups of water and stir well. (This is the mixture to be separated.)
  2. Set up a side table or counter with the supplies for the Explore (hand lenses, magnets, water, 3-oz. cups, and spoons).
  3. For each set of partners, set up 3 cups (3-oz.). In one cup, have 1 tsp. of sand, in another cup have 1 tsp. of salt, and in the third cup have 1 tsp. of iron filings.
  4. Make a chart similar to 5.5.C1: Criteria for Observations.

Engage (30 minutes)

Define a simple design problem to identify and separate materials based on their properties.

  1. Hold up Town Water Sample #2 and explain that this is the sample the town wants cleaned first. Ask students to work with a partner to review their science notebook entries from all of the lessons. What do they know about Town Water Sample #2? ESRs: From our models in Lesson 1: Town Water Samples and Lesson 2: Finding Impurities in Water, we know that there are observable particles in the water: sand and black things which we now think are iron filings. From our exploration in Lesson 3: Properties of Matter where we used the indicator, we know that there are other particles too small to be seen. We also know that the police found empty bags of iron filings, sand, salt, and sugar. So, there may be particles that are too small to be seen such as salt or sugar or even something else.
  2. Ask table groups to discuss this question: “Based on what you think might be in Town Water Sample #2, what properties of matter might you use for your design? Ask several groups to share their thinking and give groups a moment to add any new ideas to their plan.
  3. To help you in your design, you can review some of possible contaminants in the water sample. Distribute the 3-oz. cups so that each table has one of sand, one of salt, and one of iron. Give students time to review each of the substances and their properties. Make a 3-column table on the board with these headings: Sand, Salt, and Iron. Have students review in their science notebook the properties of the substances and record their ideas regarding the basic properties in each of the columns.
  4. SandSaltIron
    Does not dissolve in water
    Grainy, gritty
    Not magnetic
    Dissolves in water
    Grainy
    Not magnetic
    Does not dissolve in water
    Grainy
    Magnetic
  5. Ask the students to review their table group’s plan recorded on 5.4.H3: Environmental Engineer Design Plan to get the matter separated and identified. Now that they know the Town Water Sample is #2, does their plan still work? How will knowing the properties of the materials affect the engineer design plan? Does it still meet the criteria and constraints?
  6. After their discussion, ask partners to share any ideas they have about changing or refining their plan.
  7. Ask the class if they have any questions and record the student questions so that everyone can see them on the Class Question Board.
  8. TEACHER NOTE

    Facilitate student discussion and push students to “Ask questions to clarify and/or refine a model, an explanation, or an engineering problem.”

Explore (60 minutes plus overnight to allow evaporation)

Apply scientific ideas to solve design problems and to gather data on substances based on their unique properties.

  1. Review with the students the materials on the table that are available for creating their solution.
  2. Ask partners to use a whiteboard to draw their “plan of action.” What will they do first? What materials will they use and why? What will they do next? What materials will they use and why?
  3. Ask each set of partners to share with another set of partners their diagram and explanation of their plan.
  4. TEACHER NOTE

    Facilitate the student planning and discussion by asking specific questions about the materials they are using, what might happen if a different material was used, and why they think the material they have chosen is the best for a specific purpose. Provide these sentence frames:

    We will use _____. It is the best choice because _____. If we use _____ instead, then _____.

    This will facilitate the discussion with another set of partners when they share their plans.

  5. After sharing, ask partners to make any final changes to their design and record it in the box labeled #6 Revised Plan on 5.4.H3: Environmental Engineer Design Plan.
  6. Ask student to gather materials and set up their design solution. When the design is complete and ready for testing, give the students the large plastic cup containing the Town Water Sample (Step 1 in Advance Preparation). Ask students to record their observations and results in the box labeled #7 on 5.4.H3: Environmental Engineer Design Plan. Ask partners to refer to 5.5.C1: Criteria for Observations to support their recording of their observations.
  7. TEACHER NOTE

    The student design should include evaporation of the remaining liquid. Allow time for the liquid to stay out at least overnight and preferably over the weekend.

Explain 1 (60 minutes)

Generate and compare multiple solutions to a problem using the properties of matter to clean a water system.

  1. Have partners return to their table group. Ask them to compare their observations and results with the criteria and constraints and complete the box labeled #8 on 5.4.H3: Environmental Engineer Design Plan. Post these questions on a doc camera to help them with their discussion:
    • Why did you use this particular material? How did it work? What is your data?
    • What might be a better material to use?
    • Please explain to me how your design system works.
  2. Have a whole-class discussion of these questions.
  3. Challenge the class to think about:
    1. “Is the residue from the evaporation salt or sugar? What information is needed to answer this question?” Chart their ideas.
    2. “How efficient was their separation? Did they get back everything they started with? What information is needed to answer this question?” Chart their ideas.
    3. TEACHER NOTE

      Efficiency means how well the substances were separated. Efficiency can be evaluated by determining which team recovered the most of each substance separated with the least amount of impurities.

      Reflecting on Lesson 4: Cleaning Water, efficiency should include the idea that the separated weight and volume for each type of matter removed is the same as the starting weight and volume of the Town Water Sample.

    4. Select a question from the Design Solutions Question Board or Class Question Board that would be interesting for student to discuss. What information do they need to answer this question? Chart their ideas.
  4. Allow students to select the question they want to work on from either question board, and provide time for students to research how they might answer that question. After they have recorded their ideas in their science notebook, have them assemble in groups (based on those who worked with the same question) to share their ideas.
  5. Ask each group to make a brief presentation of their findings to the whole class.

Explain 2 (45 minutes)

Generate and compare multiple solutions to a problem using the properties of matter to clean a water system.

  1. Ask students to individually write in their science notebook reflecting on the different design processes created by their peers and the data showing how each design worked in separating the various matter in the water samples. Based on the comparison of different designs, ask students to write ideas for a best design solution for separating the substances and describe why they propose the plan, tools, and materials for separating the substances.
  2. Students share ideas as a class and add evidence to the Class Question Board and Design Solutions Question Board.
  3. (Self-assessment) Ask table groups to reflect on their process for their design by referring to 5.4.H5: Rubric (from Lesson 4: Cleaning Water). Ask them to reflect on the last four components (planning and carrying out investigations, analyzing and interpreting data, using mathematics and computational thinking, and designing solutions).

Elaborate (45 minutes)

Compare solutions used to separate substances based on their unique properties.

  1. Provide the class with Town Water Samples #1 and #3. Ask students to think about what they learned about matter separation in sample #2. Then, in their science notebook, ask them to pick either sample #1 or #3 and describe how they would separate the matter from the water.
  2. Divide the class into sample #1 and sample #3 groups and then into smaller groups of four. Have students discuss their ideas for separating their mixture. Ask them to choose the best idea.
  3. Ask groups from #1 and from #3 to share their ideas with the class, explaining which process would be the best and why.

Evaluate (35 minutes)

Make a claim about the merit of a solution and communicate solutions to clean and identify matter in contaminated water.

  1. Have students work in pairs to discuss what they learned from separating the mixture in Town Water Sample #2. Based on that information, they must develop an explanation that describes how a water filter works. They should include their understanding of:
    • particle size
    • the properties of materials that are used to identify them
    • the scale of the filter, water, and contaminants
  2. Have each pair make a poster to display outside the classroom, so that others can understand how a water filter works. Hang the posters around the school to make other students aware that contaminated water can be cleaned.
  3. Ask students to reflect in their science notebook how understanding the properties of matter and identification of matter helps them understand the anchoring phenomenon that sewage water can be made drinkable. They should state that water filtration makes sewage water safe.
  4. TEACHER NOTE

    Use the posters to assess students’ understanding of water filtration.

Resources


Download 5.5.C1