Teach students to separate observations from explanations

Design a safe classroom activity for [PHENOMENON] using [AVAILABLE MATERIALS] and [AGE GROUP]. Provide a prediction prompt, procedure, observation table, two plausible interpretations and one follow-up test that could distinguish them. Label any example results fictional rather than claiming the class observed them. Include timing, cleanup and accessibility adaptations. Do not propose hazardous chemicals or unsupported scientific claims. Check that the measurement can actually answer the question and that students are not told the conclusion before recording what they saw.