Activity 3.1: Predictions and Planning about Bread Molding (50 min)

Target Student Performance

Students (a) develop hypotheses about how matter moves and changes and how energy changes when bread molds and (b) make predictions about how they can use their investigation tools—digital balances and BTB—to detect movements and changes in matter.

Resources You Provide

(From previous lesson) Students’ ideas and questions they shared in Activity 1.2 Expressing Ideas and Questions for Bread Molding
(From previous lesson) 1.2 Expressing Ideas and Questions for Bread Molding

Resources Provided

Recurring Resources

Three Questions 11x17 Poster (1 per class)
Three Questions Handout (Color Version)
Three Questions Handout (BW Version)
(Optional) BTB Color Handout (1 per group)
(Optional) Investigation Planning Tool
Carbon TIME Bread Molding Video

Setup

Print one copy of 3.1 Predictions and Planning Tool for Bread Molding for each student. Prepare a computer and projector to display the PPT and the video. Print one copy of the Three Questions 11x17 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 and Questions for Bread Molding.

Directions

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

Show slide 2 of the 3.1 Predictions and Planning about Bread Molding PPT.

2. Watch the first half of the Carbon TIME Bread Molding Video.

Tell students that in this lesson, they will be investigating what happens when bread molds to learn more about what happens to matter and energy during chemical changes. Show slide 3 of the PPT.

Watch the Bread Molding Video until the first intermission where Darryl and Nina ask students to make predictions about what happens when bread molds.
Pause the video to discuss the questions posed on the screen before students complete the Predictions and Planning Tool.

3. Review the Matter Movement Question.

Display slide 4 of the PPT. Put a copy of the Three Questions 11x17 Poster on the wall for reference if it is not there already. Give each student one copy of the Three Questions Handout or have them take out their existing copies.

Draw students’ attention to the poster and point out that each question is accompanied with “rules to follow” as well as ways to “connect atoms to evidence.”

Have students highlight, underline, or box the following rule about matter: Atoms are bonded together in molecules.

4. Review the Matter Change Question.

Display slide 5 of the PPT.

Have students highlight, underline, or box the following rule about matter: Atoms last forever.

5. Review the Energy Change Question.

Display slide 6 of the PPT.

Have students highlight, underline or box the following rules about energy: Energy lasts forever, and energy can be transformed.

6. Have students complete Part A of the Predictions and Planning Tool for Bread Molding.

Show slide 7 of the PPT. Pass out one copy of 3.1 Predictions and Planning Tool for Bread Molding to each student and ask them to record their ideas as individuals for each of the Three Questions for Bread Molding.

Remind students that these are just predictions, and that there are no wrong answers at this point. Encourage them to write down all of their ideas on the tool.
Return students’ completed 1.2 Expressing Ideas and Questions Tool for Bread Molding You may also have typed and saved students’ ideas and questions on the 1.2 Expressing Ideas and Questions about Bread Molding PPT or you may have taken a picture of students’ sticky notes. Display the visual and review what students shared. Ask students to review their ideas and questions from the first lesson and compare them to their current predictions.

7. Discuss the Matter Movement Question as it relates to a digital balance

Show slides 8 and 9 of the 3.1 Predictions and Planning about Bread Molding PPT. Discuss with students how a digital balance can be used to measure matter moving into or out of a system. Highlight that the mass of the system can be measured before and after a change happens in a system. Discuss the two possible conclusions students can draw from their observations:

If the mass of the system increases, then matter must have moved into the system (remember the facts about atoms)
If the mass of the system decreases, then matter must have moved out of the system.

8. Discuss Matter Change Question as it relates to BTB

Show slide 10 of the 3.1 Predictions and Planning about Bread Molding PPT. Discuss with students how BTB can be used to measure matter change in a system. Highlight that the BTB in a closed container can be observed before and after a change happens in the system. Discuss the two possible conclusions students can draw from their observations:

If the BTB changes from blue to yellow, then a chemical change may be producing CO₂
If the BTB changes from yellow to blue, then a chemical change may be using CO₂ as a reactant.

9. Have students complete their predictions for Bread Molding: Part B of the Predictions and Planning Tool.

Show slide 11 of the PPT. Have students find Part B on their 3.1 Predictions and Planning Tool for Bread Molding and ask them to record their ideas as individuals for the matter movement, matter change, and energy change questions.

Remind students that these are just predictions, and that there are no wrong answers at this point. Encourage them to write down all their ideas on the tool.

10. Have students discuss their predictions in pairs.

When students have completed Part B of their Predictions and Planning Tools, show slide 12 of the PPT. Divide students into pairs and tell them to compare and contrast their predictions with each other and to look for differences and similarities.

Give students 2-3 minutes to compare their predictions. As students are sharing, circulate through the groups. Consider engaging students by: Revoice what students said/wrote (for instance, I see/hear that you think the BTB will turn blue). Why do you think that? What do you two disagree about? Why do you disagree?
Pay attention to patterns in students’ predictions as well as predictions that diverge from any of the patterns. Both will be valuable to discuss next as a whole class.

11. Have students plan the investigation: Part C of the Predictions and Planning Tool.

Show students Slide 13 of the PPT and describe the instruments and materials necessary for carrying out the investigation. Have students begin planning their investigation. There are two main variations in how much control students can have over this planning process

Minimal student control: Discuss student ideas for how an investigation could be set up. Then have students follow the lab instructions for Activity 3.2.
Maximal student control: Students in class develop their own consensus plans that will replace the lab instructions in Activity 3.2. (They may use the Investigation Planning Tool for making their plans. Note the importance of having different student groups following the same plan so that they can come to a consensus about patterns in data in Activity 3.2).
Some possible ideas of using lab materials are below:
- Students might choose to add controls to the experiment, for example including both a Petri dish of yellow bromothymol blue (BTB) (made from blowing into the blue BTB with a straw) and a Petri dish of blue BTB to the chamber.
- Students might also choose to set up a chamber with a Petri dish of blue BTB alone without the molding bread.

12. Save the Predictions and Planning Tool for later.

Display Slide 14. Tell students that they will revisit their predictions after the investigation to see how their ideas changed over time.

Assessment

The Three Questions will be a review from the Systems and Scale, Plants, and/or Animals units, but Level 2 students may still find the questions themselves hard to understand. In particular, they may be unable to connect the three columns in the Three Questions 11x17 Poster. Note whether students use facts about matter and energy as they try to answer the Three Questions.

During the class, listen to the ideas students offer in the final step of the activity. 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 decomposition. After class, use the 3.1 Assessing the Predictions Tool for Bread Molding to compare your students’ ideas with 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 bread loses mass, then atoms must be moving out of the bread? Do students account for energy separately from matter, or do they suggest that some of the matter in the bread and mold might be converted to energy or disappear? 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 3.1 Predictions and Planning Tool for Bread Molding 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 bread indicate that atoms are moving.

Differentiation

Refer back to Systems & Scale Predictions and Planning Tool as a model.
Use strategic grouping to distribute strong speakers.
Provide sentence stems for discussion and for filling in the Predictions and Planning Tool.
Read the Three Questions Handout as a group and referr back to Systems & Scale, Animals, and/or
Allow students to use their personal devices to watch the Carbon TIME Bread Molding Video with Nina and Daryl. This allows for slowdown and playback.
Give examples of predictions for each of the Three Questions and possibly post these as sentence stems for students to mirror.
Keep students’ Predictions and Planning Tools in a safe place (e.g., notebook or class file).

Modifications

Extending the Learning

Have students plan and carry out their own investigations to answer the Three Questions. If groups get unreliable data, you may want to carry out the investigations as planned in this unit, at least as a demonstration.
Have students review their observations about mold growth that they have been collecting since the Pre-Lesson. Discuss what is similar, different, or surprising about this method of growing plants compared to more familiar methods.