osmosis

osmosis- the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration. 

partially permeable membrane- a membrane with very small holes in it. only tiny molecules like water can pass through. the water molecules pass both ways because the molecules move around randomly. the stronger solution becomes more dilute because there is more water molecules on one side than the other. 

you can measure the effect of sugar solutions…