Water Testing: What Makes Water Good?

We have been learning about the chemical makeup of water and how to test water for hardness, pH, copper and chlorine. We have read and discussed what it means if the water is hard or soft, or if the pH is neutral, alkaline or acidic. Now we are going to consider the question: What makes water good?

In this investigation, your team will conduct and compare several tests on different water samples to try to determine what makes each water sample “good” and which one is the best for you to drink, to wash with, etc. Use your data to draw your conclusions.

Time Required for the Task:

Approximately five 45-minute class sessions, including four lead-up activities to learn how to do each water test.

Instructional Support Downloads

Science Task
Planning Sheet
Student Anchor Papers (pdf form)
Worksheet

Disciplinary Core Ideas

  • PS1.A

    Structure of matter

    Measurements of a variety of observable properties can be used to identify particular materials.

Additional Disciplinary Core Ideas Addressed

  • PS1.A

    Structure of matter

    Matter exists as different substances that have observable different properties.

    Different properties are suited to different purposes.

Crosscutting Concepts

  • Cause and Effect
  • Patterns
  • Structure and Function
  • Systems and System Models

Science and Engineering Practices

  • Analyzing and Interpreting Data

    Represent data in tables and/or various graphical displays (bar graphs, pictographs, and/or pie charts) to reveal patterns that indicate relationships.

    Analyze and interpret data to make sense of phenomena, using logical reasoning, mathematics, and/or computation.

  • Asking Questions and Defining Problems

    Ask questions that can be investigated and predict reasonable outcomes based on patterns such as cause and effect relationships.

    Use prior knowledge to describe problems that can be solved.

  • Constructing Explanations and Designing Solutions

    Construct an explanation of observed relationships (e.g., the distribution of plants in the back yard).

    Use evidence (e.g., measurements, observations, patterns) to construct or support an explanation or design a solution to a problem.

    Identify the evidence that supports particular points in an explanation.

  • Developing and Using Models

    Develop and/or use models to describe and/or predict phenomena.

    Use a model to test cause and effect relationships or interactions concerning the functioning of a natural or designed system.

  • Engaging in Argument from Evidence

    Construct and/or support an argument with evidence, data, and/or a model

  • Obtaining, Evaluating, and Communicating Information

    Communicate scientific and/or technical information orally and/or in written formats, including various forms of media and may include tables, diagrams, and charts.

  • Planning and Carrying Out Investigations

    Plan and conduct an investigation collaboratively to produce data to serve as the basis for evidence, using fair tests in which variables are controlled and the number of trials considered.

    Make observations and/or measurements to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

  • Using Mathematics and Computational Thinking

    Organize simple data sets to reveal patterns that suggest relationships.

    Describe, measure, estimate, and/or graph quantities such as area, volume, weight, and time to address scientific and engineering questions and problems.

Suggested materials

Items to have available during investigations include different brands of bottled water, tap water, measuring cups, small paper cups and Hach water test strips. Additional investigations might use different kinds of dish soap and distilled water.

Task Menu Quick Links

  1. Disicplinary Core Ideas
  2. Crosscutting Concepts
  3. Science and Engineering Practices
  4. Suggested materials
  5. Context
  6. Instructional stages
  7. What the task accomplishes
  8. How the student will investigate
  9. Interdisciplinary links and extensions
  10. Teaching tips and guiding questions
  11. Possible solutions

Exemplars Rubrics

Possible Solutions

In this investigation, students need to list materials used, conduct the four tests and record their data for two water samples (tap water and bottled water). Then, students should be able to write an explanation for which water sample they think is better, based on the data they collected.

Student Anchor Papers & Task-Specific Assessment Notes

This student completes the testing but fails to list the materials used. Only one result is discussed, but four tests are conducted. The numbers for hardness are questionable. There is little evidence of conceptual understanding.

This student does not meet the standard.

This student completes the testing and lists the materials used. Results reflect information read in class rather than an analysis of the test results or comparisons between the two samples. There is some evidence of conceptual understanding.

This student does not meet the standard.

This student includes a list of materials used and collects all of the data from the four tests. The discussion of results compares each quality tested and demonstrates conceptual understanding that builds on prior knowledge and experience.

This student meets the standard.

This solution includes a list of materials and data from all tests conducted. Because the students are curious, they also test seltzer – extending thinking beyond earlier investigations. The discussion of results include information learned in class, information learned through the testing, and comparisons of the data. There is clear evidence of conceptual understanding.

This student exceeds the standard.