Water Systems

Question 1

What are the key properties of water?

Answer 1

1. Polarity
2. Cohesion
3. Adhesion
4. Solvent
5. Transparency
6. High Specific Heat Capacity
7. Differences in Density
8. Differences in Gas Solubility

Question 2

What is polarity, in terms of properties of water?

Answer 2

1. H2O is a polar molecule, meaning positive/negative (- hydrogen, + oxygen)
2. Allows the formation of hydrogen bonds for water molecules with each other and other substances

Question 3

What is cohesion, in terms of the properties of water?

Answer 3

• Attraction/bonding between water molecules due to hydrogen bonding
• Allows water molecules to stick tgt and causes water droplets to form, and flow smoothly in rivers, lakes, and plants.

Question 4

What is adhesion, in terms of the properties of water?

Answer 4

Force of attraction between water molecules and other substances that carry a positive or negative charge.
Allows water to stick onto surfaces of charged object

Question 5

Explain how cohesion helped plants to transport water from roots to leaves

Answer 5

1. Supports surface tension (enabling small organisms e.g: insects to walk on water)
2. plants - helps cohesion to move from roots to leaves through capillary action

Question 6

Describe the example of water transport in plants

Answer 6

1. Xylem are tubes which carry water from roots to other parts of plant
2. Adhesion allows water molecules to STICK to xylem walls
3. At the same time, COHESION allow water molecules to stick to each other
4. The cohesion and adhesion combined create a force of tension called capillary action, pulling up water along the xylem
5. This is how water moves up as a column from the soil to other parts of a plant. It is the same force that allows drops of dew to attach to the surface of leaves.

Question 7

What are the solvent properties, in terms of the properties of water?

Answer 7

1. Able to dissolve substances easily, and are able to carry nutrients & chemicals.

Question 8

What is transparency, in terms of the properties of water?

Answer 8

• Allow light to go through, crucial for aquatic ecosystems by enabling photosynthesis in aquatic plants (phytoplankton) and algae.

Question 9

What is high specific heat capacity, in terms of the properties of water?

Answer 9

1. Absorb lots of heat before the temperature of water rises significantly.
2. Crucial for temperature regulation

Question 10

What is high density, in terms of the properties of water?

Answer 10

1. Colder water is more dense than warmer water, so it sinks below warmer water.
2. However, when water is below 4°C, it starts to expand once more and becomes less dense.
3. Prevents bodies of water from freezing solid, protecting aquatic life in water by insulating it

Question 11

Why are differences in density crucial for aquatic organisms?

Answer 11

Floating ice insulates the water below, keeping it liquid and providing a habitat for fish and other organisms even in freezing conditions.

Question 12

Why is high specific heat capacity crucial for aquatic organisms?

Answer 12

• Regulate temperature helps maintain stable climates and ecosystems.
• It also protects organisms from rapid temperature fluctuations.

Question 13

What is thermohaline circulation and what is it also referred as?

Answer 13

A global system of ocean currents driven by differences in temperature and salinity. Also referred as the ocean conveyor belt.

Question 14

Why is the Ocean a carbon sink?

Answer 14

Anything that absorbs and stores more CO2 from the atmosphere, than it releases, and the ocean is a huge carbon sink

Question 15

How does the ocean act as a carbon sink?

Answer 15

1. CO2 directly dissolves into oceans, colder water absorb more than warmer water, making polar oceans more effective
2. Phytoplanktons absorb CO2 for photosynthesis processes
3. Ocean conveyor belt, transport CO2 from deeper waters
4. CO2 react with seawater to form carbonic acid, further disassociating into bicarbonate and carbonate ions (chemical forms of carbon) which remain in the ocean.

Question 16

Risks of carbon sequestration/sink?

Answer 16

1. Ocean acidifcation -> seawater + CO2 form carbonic acid, decrease pH of water -> dissolve/weaken calcium-carbonate forming shells organisms
2. Inrease global temperatures, affect the efficiency of the ocean being a carbon sink as less CO2 is absorbed.
3. Increased stratification

Question 17

What is the long-term effects of carbon sequestration?

Answer 17

1. decomposed organisms remain as organic carbon, which sink to the ocean floor. this biomass is decomposed but not all of it breaks down completely.
2. This accumulation of partially decomposed organisms results in sedimentation on the seabed = long-term stores of carbon

Question 18

What is The Role of Sedimentation in Carbon Sequestration?

Answer 18

1. They become fossil fuels (carbonification)
2. The extraction and burning of fossil fuels release this stored carbon back into the atmosphere, contributing to CO₂ emissions and climate change.