Lesson 5 of 11
Objective: SWBAT create a model of a water molecule, describe its properties, and predict the types of bonds it will create as a result of its structure.
This video explains the key aspects of this lesson as students review the structure and function of water molecules through their analysis of collaborative student-made clay models that demonstrate the types of bonds found in a water molecule.
Students will watch the video clip and record five facts about the importance of water in Biology. This video clip does a fantastic job introducing/reviewing relevant vocabulary terms that are essential to comprehend for this lesson regarding the properties of water.
As a follow-up to the video, the class will engage in a short discussion regarding the significant role water plays in our lives. Students will brainstorm all aspects of their lives that water plays an essential role for our survival. The teacher will provide three categories to jump start the students' efforts and will encourage all students to be specific and creative:
- Water's Role in our Body's Physiology:
- Water's Role in our Environment:
- Water's Role in our Home:
Students have a prior knowledge of the structure of water, but most students are unable to transfer their understanding of the H2O structure into being able to make predictions regarding water bonding or water properties. The Properties of Water Lecture Notes will provide students a more detailed look into the structure of water and its vital role in our study of Biology.
Students will get out a sheet of paper and title it, "Water's Role In Biology"in preparation for this class discussion and notes.
The last few slides of the presentation review the disassociation of water into ions and the pH scale. If there is time in the lesson, these slides will be reviewed. If not, the curriculum regarding acids and bases will be saved for the next lesson.
Each student pair is given their necessary supplies:
- Two colors of clay to represent the Hydrogen (red clay) and Oxygen (blue clay) atoms
- A third color (yellow clay) to represent the valence electrons (which will assist the students in visualizing the covalent bonds)
- Coffee stirrers to represent the covalent bonds
- Toothpicks to represent the hydrogen bonds between water molecules
Students are provided the supplies and provided very little other directions, except the color assignment, to create their water molecules. Each student pair will create two water molecules using covalent bonds. Then the students will use the toothpicks to connect the two water molecules to represent the hydrogen bonds. Once the students have been given approval from the teacher that their models are chemically correct, they can find another group to join their molecules by creating additional hydrogen bonds. Students can continue to build their structure until the whole class has contributed to the collaborative model. The resulting clay model will be very large so make sure you have plenty of space to work!
Sample Image of Water Molecule -single water molecule and bonded water molecules. Students used the color code described above and created these simple models to demonstrate their understanding of the water molecule and hydrogen bonds.
The students are encouraged to observe the final collaborative model and record their findings.
Student partners will discuss the following questions and record their response on their own sheet of paper:
- How does the class model differ from the single water molecule? (think bonds!)
- What are the strengths of our water model? How is it correct?
- What are the weaknesses of our water model? How is it incorrect?
- How do the bonds that you observe allow for the versatility of water in our lives?
The class will review the student responses in a whole group discussion.
Water Sculpting: Student Reflection: Students responded to these four questions to analyze the accuracy of their clay water models. Students seemed to need more support than expected when determining the accuracy of their models. This confusion demonstrates our students' need to think beyond the obvious and progress deeper in their thought process by connecting their understanding between lecture, lab activities, and the real world application.
Students will share their experiences during the water sculpting activity. The discussion will focus on the types of bonds present in water, the chemical reactivity of the elements in water, and predicting what types of compounds hydrogen and oxygen can make.
Students will complete this Properties of Water Review to reinforce today's lesson.
Sample of Student Work: Water Properties Practice Questions - Student understanding seemed to improve when students were able to demonstrate their comprehension through basic review questions. It is imperative with the NGSS to encourage students to move beyond their comfort zone and begin demonstrating their learning through modeling and real-world applications.