Diffusion
Diffusion is the movement of particles from an area of ______ concentration to an area of ______ concentration.
From high concentration to low concentration.
Osmosis is the movement of this substance across a selectively permeable membrane.
Water.
This process sends water from Earth's surface into the atmosphere as water vapor when the sun heats liquid water.
Evaporation.
Water can exist in three states. Name these states.
Solid (ice), liquid (water), gas (water vapor).
Give a simple classroom example of diffusion using a drop of food coloring in water. What happens over time?
The food coloring spreads out from the drop (high concentration) until it is evenly distributed (low concentration) in the water.
Define "selectively permeable membrane" in one sentence.
A membrane that allows some substances (like water) to pass through but blocks others.
Name the process where water vapor cools and changes back into liquid droplets, forming clouds.
Condensation.
Water is represented by the chemical formula
H20
How does temperature affect the rate of diffusion in liquids? Explain why.
Higher temperature increases the rate of diffusion because particles move faster and spread out more quickly.
Predict what happens to a plant cell placed in a very salty (hypertonic) solution: does it gain water, lose water, or stay the same? Explain briefly.
The plant cell will lose water and shrink (plasmolysis) because water moves out to the higher solute concentration.
This is the movement of water from plants to the atmosphere through tiny openings in leaves.
Transpiration.
Water is made of molecules, and each molecule is made of ________________________
two hydrogen atoms and one oxygen atom
In the lungs, oxygen moves from the air sacs into the blood by diffusion. Explain why oxygen moves in that direction (refer to concentration gradients).
Because oxygen concentration is higher in the air sacs (alveoli) than in the blood, oxygen diffuses down its concentration gradient into the blood.
When a plant cell is placed in a solution with a high solute concentration, it will ____________________
lose water and shrivel
When water flows over the ground surface into streams and rivers instead of soaking into the soil, it is called this.
Runoff
Power generated by water is referred to as
Hydropower
Compare and contrast diffusion and active transport (list one similarity and one key difference).
Similarity: Both move substances across membranes. Difference: Diffusion is passive (no energy needed) while active transport requires cellular energy (ATP) to move substances against a concentration gradient.
The greater the distance water molecules have to travel across the membrane, the ________ the rate of osmosis.
Slower
Describe the full sequence of steps in the water cycle using the terms evaporation, condensation, precipitation, and collection.
Evaporation → Condensation → Precipitation → Collection
Pure water have a pH of
7