demoTK1 meetingMeeting 28

Color-Climbing Celery

Three related teacher demonstrations: Color-Climbing Celery, Coin Appears When Water Is Added, Bent Pencil in Water.

Teaching & key ideas

1. Color-Climbing Celery Materials: Celery stalk/white flower; colored water What you do: Show a stalk prepared earlier in colored water; cut stem if desired. What students see: Colored veins/petals appear. Question: Where did the color travel inside the plant? 2. Coin Appears When Water Is Added Materials: Opaque cup; coin; water What you do: Position viewer so rim hides coin, then add water without moving viewer. What students see: The coin appears. Question: Did the coin move? 3. Bent Pencil in Water Materials: Clear cup; water; pencil/straw What you do: Place pencil partly in water and view from the side. What students see: It looks bent or broken at the surface. Question: Is the pencil really bent?

Lesson flow

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: Where did the color travel inside the plant? Question: Did the coin move? Question: Is the pencil really bent?