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Systems and Scale | Activity 4.1

Activity 4.1: Predictions about Ethanol Burning (20 min)

Students use the Predictions Tool to record their predictions about what happens when ethanol burns.

Materials You Provide

  • (From previous lesson) Students’ ideas and questions they shared in Activity 1.2 Expressing Ideas Tool for Ethanol Burning
  • (From previous lesson) 1.2 Expressing Ideas Tool for Ethanol Burning
  • Video or demonstration of ethanol burning

Resources Provided

Setup

Print one copy of 4.1 Predictions Tool for Ethanol Burning for each student. Prepare a computer and projector to display the PPT and the video. Print one copy of the Three Questions 11 x 17 Poster and display it on your classroom wall. Print one copy of the Three Questions Handout for each student. Retrieve the materials from Activity 1.2. This may include a PPT slide from the lesson in which you typed students' responses or a photograph of their sticky notes as well as the students' completed 1.2 Expressing Ideas Tool for Ethanol Burning.

Directions

1. Use the instructional model to show students where they are in the course of the unit.

Assessment

The Three Questions will be new to students, and Level 2 students will find the questions themselves hard to understand. In particular, they will initially be unable to connect the three columns in the Three Questions 11 x 17 Poster.

  • The question itself: Note whether students use the “Facts about atoms and molecules” that they studied in Lesson 2 as they try to answer the Matter Movement and Matter Change Questions. .
  • Rules to follow: The most important rule (and the first Fact about Atoms) is: Atoms last forever. Do they follow that rule when they try to answer the questions?
  • Evidence to look for: Students will address this column in more depth when they do the investigation. One thing to note for now: When students see gas bubbles leaving the soda water, do they cite that as evidence that atoms are leaving the soda water? Do they suggest ideas about what gas might be in the bubbles? Note whether students connect bubbles leaving soda water with atoms leaving soda water.
  • During the class, listen to the ideas students offer in the final step of the activity. At this point do students’ predictions follow the rules? At this point, do not correct student ideas, but listen for what they say about matter and energy in the context of combustion. After class, use the 4.1 Assessing the Predictions Tool for Ethanol Burning to compare your students’ what we would expect to see in Level 4 responses.  

This discussion will show that some students are still at Level 2 with respect to both their ideas about energy and their understanding of the questions. For example, do students have a sense of necessity about the connections between mass changes and movement of atoms? Do they recognize that if the ethanol loses mass, then atoms must be moving out of the ethanol? Do students account for energy separately from matter, or do they suggest that some of the matter in the ethanol might be converted to energy? You do not need to correct any problems now; they will be addressed through the investigation and Modeling in the Activities to come.

Tips

  • Have a designated place in the classroom where students store their Predictions Tool so they can easily refer back to their ideas at the end of the lesson.
  • Expect many students to make the right predictions for the wrong reasons. Note in particular whether they say that changes in the mass of the ethanol indicate that atoms are moving.