Materials List:
– 1 bar of Ivory soap
– Bowl of water
– Dinner plate
– Knife (for cutting the soap)
– Microwave
– Chart or paper for recording predictions and observations
– Optional: Other brands of soap for comparison
– Sensory table or container (for further exploration after the experiment)

Preschool Learning Objectives:
1. Science and Experimentation: Introduce preschoolers to basic scientific concepts like observation, prediction, and testing. Encourage understanding of cause and effect (e.g., how microwaving soap causes it to expand).

2. Sensory Exploration: Engage the five senses (sight, touch, smell, hearing, and taste) as children observe and feel the changes in the soap’s texture and appearance.

3. Critical Thinking and Problem Solving: Foster curiosity and critical thinking as children predict and then observe what happens during the experiment. Discuss the difference between their predictions and the actual results.

4. Mathematical Concepts: Introduce measurement and counting concepts (e.g., measuring time in seconds and comparing the size of the soap before and after microwaving).

5. Language and Communication: Expand vocabulary through descriptive language (e.g., “expand,” “bubbles,” “soft,” “solid,” “airy”) and encourage children to describe what they observe.

Teacher Instructions:
1. Introduction to the Experiment:
Begin by discussing the scientific method with your preschoolers. Ask them to predict what they think will happen to the bar of soap when it’s placed in the water or microwaved. Record their predictions on a chart to revisit later.

2. Experiment #1: Floating Test
Place the Ivory soap in a bowl of water to see if it floats. Ask the children to predict whether the soap will float or sink. After observing the results, engage the children in a conversation about why they think the soap floated or didn’t. Touch the soap and discuss the texture (solid, airy) and how it feels in their hands.

3. Experiment #2: Soap Cloud Expansion
Cut the soap into four pieces and place them on a dinner plate.
Ask the children to predict what will happen when the soap is microwaved. Microwave the soap for 1 minute. Open the microwave after about 30 seconds to show the soap’s changes and continue to watch the process.

After the full minute, remove the soap carefully and allow it to cool for a few minutes before letting the children touch it. Encourage children to describe the changes they observe (e.g., texture, size, appearance, smell).

4. Exploring the Science:
Explain to the children that Ivory soap has tiny air pockets inside it, making it lighter than other soaps. When microwaved, the heat causes the water molecules inside the soap to expand, which causes the soap to puff up. Discuss how the soap texture has changed from solid to spongy and why that happens.

5. Sensory Exploration:
After the soap has cooled, place it in a sensory table for children to further explore the texture and shape. Allow them to manipulate and explore the soap with their hands.

6. Extend the Learning:
You can extend this experiment by comparing the results with other brands of soap. Discuss how different soaps behave when microwaved and compare the texture, smell, and overall result. Use charts to compare the size of the soap before and after the experiment, further reinforcing counting and measurement.

Tips for Differentiated Instruction:

For children who need additional support:
Offer extra guidance during the experiment, especially when making predictions. Provide simple cues to help them focus on what to look for (e.g., “Let’s see if the soap gets bigger!” or “How does the soap feel when we touch it?”).

For children who need more of a challenge:
Encourage them to make predictions about other variables, such as using a different brand of soap. Have them compare their results more carefully (e.g., size, texture, time it takes to expand).

For children with sensory sensitivities:
If needed, limit the sensory play and allow them to observe the changes without physically touching the soap. Focus on the visual and auditory aspects (e.g., the sound of the soap expanding in the microwave or the bubbling effect).

Assessment Suggestions:
1. Observation of Predictions and Observations:
As the children make predictions, observe how accurate they are. Did they understand the concept of floating and expanding? Were they able to articulate their ideas clearly?
Observe how children describe the soap after the experiment. Are they using new vocabulary like “expands,” “bubbles,” or “soft”? Are they able to articulate the differences between the pre- and post-experiment soap?

2. Language and Communication Skills:
Assess how children express themselves during the experiment. Do they participate in group discussions and contribute their observations? Are they able to explain what they observed in their own words?

3. Critical Thinking and Problem Solving:
Take note of how the children approach the experiment. Are they asking questions, wondering about cause and effect, or suggesting new ways to test the soap?

4. Sensory Exploration:
Observe how children engage with the sensory table. Are they actively exploring the soap? Do they show curiosity about how it feels or smells? Are they making connections between the sensory experience and the changes they saw during the experiment?