Science Experiments Ideas
Dissolve a teaspoonful of salt in a glass of water and cover
it tightly with parchment paper. Place the glass upside down
in a dish containing water strongly coloured with vegetable
dye. Although the parchment paper has no visible holes; the
water in the glass is soon evenly coloured. The tiny particles
of water and dye pass through the invisible pores in the
parchment paper. We call such an exchange of liquids through a permeable membrane, osmosis.