A Scoop of Science: Mini Ice Cream - Reversible or Not?

Part 1: Mini Ice Cream Making and Observing (30-40 minutes)

(1) Engage (5 minutes):

• Begin by reminding students about their favorite frozen treats and how they think they become solid.

(2) Explore (20-25 minutes):

• Introduce the Experiment: Explain that today they will each be scientists making their own tiny cup of ice cream to see what happens when we cool a small amount of liquid.
• Safety First: Remind students not to open the bag until instructed and to be careful handling the cold bags and salt.
• Step-by-Step Mini Ice Cream Making (Guide students through each step):
  1. Prepare the Ice Bath: In the bag, have students add the ice and rock salt. Explain again that the salt helps the ice get much colder.
  2. Set Up Ingredients: Have each student take their individual creamers and place them into their bag. Seal the bag tightly, removing as much air as possible.
  3. Shake and Observe: Have students shake and massage their bags for about 5-10 minutes. Encourage them to feel the temperature of the bag and observe any changes happening inside. Ask guiding questions:
     • "What does the bag feel like?" (Cold)
     • "What do you think is happening to the liquid inside the small bag?" (It's getting thicker, starting to look like soft ice cream)
     • "How is it different from the creamy liquid we started with?"

(3) Explain (5-10 minutes):

• Discuss the Change: Gather students to discuss their individual results.
  • "What happened to your coffee creamer in the bag?" (It got cold and turned into a soft solid/ice cream)
  • "What made it get colder?" (The coldness from the ice and salt went into the bag)
  • "What was the coffee creamer like before?" (A liquid) "What is it like now?" (A soft solid)
  • "So, what did cooling do to the liquid coffee creamer in your bag?" (It changed it into a soft solid)

Part 2: Reversible vs. Irreversible Changes (30-35 minutes)

(4) Elaborate (15-20 minutes):

• The Reversible Change: Ask students: "What do you think will happen to your mini ice cream if we leave it out for a little while?" (It will melt back into a liquid).
• Explain again that this is a reversible change because we can change the material back to its original form by changing the temperature (warming it up).
• Review Irreversible Changes: Briefly revisit the examples of irreversible changes caused by heating or cooling (baking a cake, burning wood, etc.), asking students to recall why those changes are difficult or impossible to undo.

(5) Evaluate (10-15 minutes):

• Independent Worksheet: Distribute the performance task (linked in the resources tab). Have students complete it individually, drawing and writing to explain their observations and understanding of reversible and irreversible changes.

Differentiation: Provide sentence starters on the worksheet. Offer a simplified version of the worksheet with fewer questions or more visual prompts. Allow them to dictate their answers to a teacher or paraprofessional.

Extension: Challenge them to predict what would happen if they used different amounts of salt or ice. Ask them to research other examples of reversible and irreversible changes and add them to their worksheet. Encourage them to write more detailed explanations.

• Observe student participation in discussions.
• Review the completed performance tasks for evidence of understanding reversible and irreversible changes caused by heating and cooling.