Water Properties & Movement Quiz

Water Molecules & Properties

• Water molecules are polar, with an uneven distribution of charges.
• Adhesion is water sticking to other surfaces, cohesion is water sticking to itself.
• Surface tension, due to cohesion, allows small insects to walk on water. Hydrogen bonds are responsible.
• Density is mass per unit volume (Density = Mass / Volume).
• To increase density, decrease volume. Increase by cooling, decrease by heating.
• Irregular objects' volume is found using Archimedes' principle (measuring displaced water).
• An object floats if its density is less than water's (1 g/cm³), sinks otherwise.

Diffusion & Osmosis

• Diffusion is the movement of molecules from high to low concentration until equilibrium.
• Osmosis is the diffusion of water across a partially permeable membrane from high to low water concentration.
• Partially permeable membranes allow specific molecules (e.g., water) through small holes, blocking others.
• In both diffusion and osmosis, concentration gradients are equalized. However, diffusion involves both solutes and solvent, while osmosis only involves solvent (water) movement.
• Osmosis moves water from low solute concentration to high solute concentration to balance solute concentration.
• Too much water swells cells (possibly bursting); too little water shrinks cells, hindering function.

Transpiration

• Transpiration is the process of water movement through plants and release into atmosphere. It helps plants cool and transports nutrients.
• Xylem cells transport water from roots to leaves; they are hollow and strong.
• Root hair cells absorb water and nutrients; their thin, extensive hairs maximize surface area.
• Stomata are small leaf openings letting gases in/out; guard cells regulate stomata, controlling water loss and gas exchange for photosynthesis.
• Light increases transpiration (more stomatal opening); high humidity slows it; moving air speeds it up (removes water vapor around the plant).

Air & Gas Behavior

• Gases fill their container.
• Pressure increases with more molecules or higher temperature.
• Temperature increases, gas speeds up and spreads out, increasing pressure (if volume is fixed).
• Gas molecules move quickly and randomly.
• Increased temperature = increased speed of gas molecules, increased pressure if constant volume.
• Decreased volume = increase in molecular collisions; increased pressure.

Photosynthesis & Respiration

• Photosynthesis: Carbon dioxide + water + light energy → glucose + oxygen
• Respiration: glucose + oxygen → carbon dioxide + water + energy
• Aerobic respiration occurs within the cell (not specified where).

Test your understanding of water molecules, their properties, and the processes of diffusion and osmosis. Explore concepts such as adhesion, cohesion, density, and the principles governing the movement of molecules. This quiz will help reinforce your knowledge of fundamental chemistry and biology principles.