Water Dome on a Penny
Water forms a raised dome before spilling.
Teaching & key ideas
What you do: Add drops one at a time to a penny.
What students see: Water forms a raised dome before spilling.
Why it works: Cohesion and surface tension hold the water together.
Question to ask: How can water rise above the edge?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: How can water rise above the edge?