Osmosis

• Osmosis is the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.
• A partially permeable membranes is just one that has very small holes in, so only tiny molecules such as water can pass through but bigger molecules such as sucrose can't.
• The water molecules can pass both ways through the membrane during osmosis. This happens because water molecules move around randomly all the time.
• Because there are more water molecules on one side than the other, there's a steady net flow of water into the region with fewer water molecules, e.g. into the stronger sugar solution.
• Meaning the strong sugar solution gets more diluted as the water is trying to 'even up' the concentration.
• Osmosis is a type of diffusion-passive movement of water molecules from an area of higher water concentration to an area of lower concentration.