Clear Water Beads 'Vanish'
Invisible-looking beads appear on spoon.
Teaching & key ideas
What you do: Show apparently empty water, then scoop hidden beads.
What students see: Invisible-looking beads appear on spoon.
Why it works: Similar refractive index reduces visible boundaries.
Question to ask: How can something be there but hard to see?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: How can something be there but hard to see?