Engage: Scholars learn of the scarcity of fresh, clean water on Earth. They are invested in understanding how Earth’s water came to be this way and how scientists are fighting a life and death battle to clean it up.
- Lesson 1: Dirty Water. What’s in the water we drink? Is our tap water really pure water? Is it safe? Scholars explore these questions and more during this introductory lesson.
- Lesson 2: The Global State of Water. Scholars study the global state of water to learn why scientists are so invested in maintaining a clean supply of drinking water on Earth. Through their exploration, they will invest in the unit’s Essential Question and begin to see scientists and engineers as agents of change.
Explore: Everywhere you look, the Earth’s water has a variety of contaminants. Some occur naturally and others are the result of human activity, but they all need to go before the water is safe to use or consume! Scholars tackle a variety of challenges to separate unwanted materials from water samples.
- Lesson 3: Removing Solid Particles. Scholars will attempt to separate unwanted sand and pebbles from water. They will discover filtration as an effective method for removing solid particles.
- Lesson 4: Removing Dissolved Particles. Scholars tackle a new challenge: How does one remove contaminants from water if they’ve already dissolved into it?
- Lesson 5: Removing Other Liquids. Scholars are challenged to create a procedure to separate multiple liquids to isolate water!
Explain: Separating water with multiple contaminants requires a deeper understanding of physical properties. The properties of a substance such as hardness, material, and polarity can all help scientists determine the best method of separation. Additionally, certain factors such as temperature and agitation can affect the rate of solubility.
- Lesson 6: Physical Properties. Scholars are challenged to apply multiple techniques to isolate clean water from a mixture containing three unknown ingredients.
- Lesson 7: Solubility. Scholars will study solubility to learn more about how the Earth’s water ended up having so many other particles dissolved in it.
- Lesson 8: Changing Solubility. Scholars will develop their own procedures to study how rates of solubility can change under specific conditions.
- Lesson 9: Graphing Solubility. Scholars will learn how to read a solubility graph. Through careful study of real solubility curves, scholars will identify additional data to support their conclusions from the previous lesson.
Elaborate: Scholars use their knowledge of physical properties and solubility in new ways as they explore two new applications: panning for gold and making refreshing, bubbly soda pop!
- Lesson 10: Panning for Gold. Scholars will take a step back from their study of the world’s water to study the separation of mixtures in a new context: panning for gold!
- Lesson 11: Fizz, Fizz, Pop! Scholars study the separation of mixtures in another new context: the creation of soda pop! Scholars learn why soda is served cold.
Evaluate: Armed with all their knowledge from this unit, scholars are ready for the final challenge: engineer solutions to clean up some very dirty water! Scholars will apply their understanding of how scientists clean up the world’s water to separate unwanted particles and solvents from a water sample.
- Lesson 12: The Dirty Water Design Challenge: Introduction and Planning. Scholars create a plan to tackle their final challenge; engineer a system for cleaning a sample of very dirty water!
- Lesson 13: The Dirty Water Design Challenge: Implementation and Reflection. Scholars will test the efficacy of their designs, make revisions, and reflect on their work. Scholars will revisit the Essential Question for the last time as they issue a final statement.