• Opaque bags or boxes (one per group)
• Collection of objects with varied properties (smooth/rough, heavy/light, magnetic/non-magnetic)
• Recording sheets for observations
• Hand lenses (optional)

Fill bags with 5-8 objects that illustrate properties of matter: metal spoon, cotton ball, rubber band, wooden block, plastic toy, etc. All bags have identical objects. Create recording sheets.

1. Place mystery bags on tables before students enter. Build anticipation: 'Don't touch yet!'
2. Explain: 'You're scientists investigating unknown objects. Your job: observe, describe, and question.'
3. Rules: One object at a time. Use all senses except taste. Everyone records observations.
4. Round 1 (5 min): Without opening bags, feel from outside. What do you notice? Record predictions.
5. Round 2 (10 min): Open bags. Examine each object. Record observations: What does it look like, feel like, sound like?
6. Guiding questions: How are these objects similar? Different? How could you group them?
7. Generate questions: What do you wonder about these objects?
8. Whole class: Share observations and questions. Introduce vocabulary (texture, mass, flexibility).
9. Transition: 'Today we'll investigate properties of matter using the vocabulary scientists use.'

Provide observation sentence stems for younger students. Include familiar and unfamiliar objects. For advanced students, add objects that challenge categorization.

Evaluate quality of questions generated. Check observations for use of descriptive vocabulary. Note hypotheses that show scientific thinking. Connect to formal vocabulary during lesson.