Practice Flashcards
What is the hydrological cycle?
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All Flashcards in Topic 4.1
Below are all 150 flashcards for this topic. Sign up free to track your progress and get personalized review schedules.
4.1.170 cards
What is the hydrological cycle?
The continuous movement of water between atmosphere, land, and oceans through evaporation, condensation, precipitation, infiltration and runoff.
One-sentence definition.
Define evaporation in the water cycle.
Evaporation is liquid water changing to water vapour from non-living surfaces such as oceans, lakes, rivers or wet soil, absorbing latent heat.
Non-living surfaces.
Why does condensation cause warming?
When water vapour condenses (gas to liquid), molecular bonds form and energy is released to the surroundings. The surroundings gain energy and warm up.
Form bonds → energy out.
State the system type of the global hydrological cycle for matter and for energy.
Matter: closed (same water recycled). Energy: open (solar energy enters, heat leaves).
Closed vs open.
Define evaporation in the water cycle.
Evaporation is liquid water changing to water vapour from non-living surfaces such as oceans, lakes, rivers or wet soil, absorbing latent heat.
Non-living surfaces.
Define evapotranspiration.
Evapotranspiration is the combined total water loss from an area through both evaporation and transpiration.
Evaporation + transpiration.
Why does evaporation cause cooling?
Evaporation requires energy to break bonds between water molecules. This energy is absorbed from the surroundings, so the surroundings lose energy and cool down.
Break bonds → energy from surroundings.
Define evapotranspiration.
Evapotranspiration is the combined total water loss from an area through both evaporation and transpiration.
Evaporation + transpiration.
What is a phase change in the water cycle?
A change of state of water, such as liquid to gas (evaporation) or gas to liquid (condensation).
State change.
Why does condensation cause warming?
When water vapour condenses (gas to liquid), molecular bonds form and energy is released to the surroundings. The surroundings gain energy and warm up.
Form bonds → energy out.
State the system type of the global hydrological cycle for matter and for energy.
Matter: closed (same water recycled). Energy: open (solar energy enters, heat leaves).
Closed vs open.
Why does evaporation cause cooling?
Evaporation requires energy to break bonds between water molecules. This energy is absorbed from the surroundings, so the surroundings lose energy and cool down.
Break bonds → energy from surroundings.
What is the hydrological cycle?
The continuous movement of water between atmosphere, land, and oceans through evaporation, condensation, precipitation, infiltration and runoff.
One-sentence definition.
What is a phase change in the water cycle?
A change of state of water, such as liquid to gas (evaporation) or gas to liquid (condensation).
State change.
Name three major stores of water on Earth.
Oceans, ice/glaciers, and groundwater (also rivers/lakes, atmosphere, living things).
Stores = where water is held.
Define latent heat in one sentence.
Latent heat is the “hidden” energy absorbed or released during a phase change without changing temperature.
Hidden energy.
Give two everyday examples of evaporative cooling.
Examples include sweating cooling the body, feeling cold after swimming as water evaporates from skin, wet clothes making you feel colder, or a wet cloth cooling a fever.
Skin + evaporation.
Define latent heat.
Energy absorbed or released during a phase change without a change in temperature.
Hidden energy.
Define latent heat.
Energy absorbed or released during a phase change without a change in temperature.
Hidden energy.
Name three factors that increase evapotranspiration.
Higher temperature, lower humidity, and stronger wind increase evapotranspiration (also greater vegetation cover and higher water availability).
Hot, dry, windy.
Give two everyday examples of evaporative cooling.
Examples include sweating cooling the body, feeling cold after swimming as water evaporates from skin, wet clothes making you feel colder, or a wet cloth cooling a fever.
Skin + evaporation.
Name three major stores of water on Earth.
Oceans, ice/glaciers, and groundwater (also rivers/lakes, atmosphere, living things).
Stores = where water is held.
Define transpiration in the water cycle.
Transpiration is the loss of water vapour from living plants through stomata in leaves, absorbing latent heat.
Plants + stomata.
Give one example where condensation releases heat.
Examples include storms/hurricanes intensifying as condensation releases latent heat, a warm bathroom after a hot shower as steam condenses, or steam burns being severe when steam condenses on skin.
Condensing steam releases heat.
Give one example where condensation releases heat.
Examples include storms/hurricanes intensifying as condensation releases latent heat, a warm bathroom after a hot shower as steam condenses, or steam burns being severe when steam condenses on skin.
Condensing steam releases heat.
Define transpiration in the water cycle.
Transpiration is the loss of water vapour from living plants through stomata in leaves, absorbing latent heat.
Plants + stomata.
Name three factors that increase evapotranspiration.
Higher temperature, lower humidity, and stronger wind increase evapotranspiration (also greater vegetation cover and higher water availability).
Hot, dry, windy.
Define latent heat in one sentence.
Latent heat is the “hidden” energy absorbed or released during a phase change without changing temperature.
Hidden energy.
Explain (3 marks) condensation warming in exam style.
(1) Condensation releases energy when molecular bonds form. (2) This energy is transferred to the surroundings. (3) The surroundings gain energy so temperature increases (warming).
3 steps.
Name three flows in the hydrological cycle.
Evaporation, precipitation, and runoff (also transpiration, condensation, infiltration, percolation).
Flows = how water moves.
How does humidity affect evapotranspiration?
Low humidity increases evapotranspiration because dry air can accept more water vapour, maintaining a strong diffusion gradient from surfaces and leaves.
Dry air = more “room”.
What is the key difference between evaporation and transpiration?
Evaporation occurs from non-living surfaces, while transpiration occurs from living plants (via stomata).
Non-living vs plants.
Explain (3 marks) evaporative cooling in exam style.
(1) Evaporation requires energy to break molecular bonds. (2) This energy is absorbed from the surroundings. (3) The surroundings lose energy so temperature decreases (cooling).
3 steps.
During evaporation, is latent heat absorbed or released?
Absorbed. Energy is required to break bonds as liquid water becomes water vapour.
Breaking bonds needs energy in.
Name three flows in the hydrological cycle.
Evaporation, precipitation, and runoff (also transpiration, condensation, infiltration, percolation).
Flows = how water moves.
Complete the trio: evaporation, transpiration, evapotranspiration.
Evaporation = from non-living surfaces. Transpiration = from plants (stomata). Evapotranspiration = both combined total water loss.
Non-living, plants, both.
How does humidity affect evapotranspiration?
Low humidity increases evapotranspiration because dry air can accept more water vapour, maintaining a strong diffusion gradient from surfaces and leaves.
Dry air = more “room”.
Complete the trio: evaporation, transpiration, evapotranspiration.
Evaporation = from non-living surfaces. Transpiration = from plants (stomata). Evapotranspiration = both combined total water loss.
Non-living, plants, both.
What is the key difference between evaporation and transpiration?
Evaporation occurs from non-living surfaces, while transpiration occurs from living plants (via stomata).
Non-living vs plants.
Explain (3 marks) condensation warming in exam style.
(1) Condensation releases energy when molecular bonds form. (2) This energy is transferred to the surroundings. (3) The surroundings gain energy so temperature increases (warming).
3 steps.
Explain (3 marks) evaporative cooling in exam style.
(1) Evaporation requires energy to break molecular bonds. (2) This energy is absorbed from the surroundings. (3) The surroundings lose energy so temperature decreases (cooling).
3 steps.
During evaporation, is latent heat absorbed or released?
Absorbed. Energy is required to break bonds as liquid water becomes water vapour.
Breaking bonds needs energy in.
During condensation, is latent heat absorbed or released?
Released. Energy is transferred to the surroundings as bonds form when vapour becomes liquid.
Forming bonds releases energy out.
Why can forests cool local climate?
Trees transpire large amounts of water vapour. This transpiration absorbs latent heat from the surroundings, lowering local air temperature.
Transpiration = cooling.
Why does wind increase evapotranspiration?
Wind removes moist air from the surface/leaf boundary layer and replaces it with drier air, increasing evaporation and transpiration rates.
Moves moist air away.
For 4 marks: outline how energy is transferred in the water cycle.
Solar energy drives evaporation. Latent heat is absorbed during evaporation (cooling). Latent heat is released during condensation (warming). This transfers and redistributes heat within the atmosphere.
Solar → evap; latent heat in/out.
During condensation, is latent heat absorbed or released?
Released. Energy is transferred to the surroundings as bonds form when vapour becomes liquid.
Forming bonds releases energy out.
Do evaporation and transpiration absorb or release latent heat?
Both absorb latent heat from the surroundings during the liquid to gas phase change, producing a cooling effect.
Both cool.
For 4 marks: outline how energy is transferred in the water cycle.
Solar energy drives evaporation. Latent heat is absorbed during evaporation (cooling). Latent heat is released during condensation (warming). This transfers and redistributes heat within the atmosphere.
Solar → evap; latent heat in/out.
In the global water cycle, is matter open or closed? What about energy?
Matter is closed (no net water enters or leaves Earth). Energy is open (solar energy enters and heat energy leaves).
Closed for matter, open for energy.
Do evaporation and transpiration absorb or release latent heat?
Both absorb latent heat from the surroundings during the liquid to gas phase change, producing a cooling effect.
Both cool.
In the global water cycle, is matter open or closed? What about energy?
Matter is closed (no net water enters or leaves Earth). Energy is open (solar energy enters and heat energy leaves).
Closed for matter, open for energy.
How does latent heat help redistribute energy globally?
Energy is absorbed at Earth’s surface during evaporation (often in warm regions) and released higher in the atmosphere during condensation, transferring heat and helping move energy around the planet.
Absorbed low, released high.
Why does wind increase evapotranspiration?
Wind removes moist air from the surface/leaf boundary layer and replaces it with drier air, increasing evaporation and transpiration rates.
Moves moist air away.
How does latent heat help redistribute energy globally?
Energy is absorbed at Earth’s surface during evaporation (often in warm regions) and released higher in the atmosphere during condensation, transferring heat and helping move energy around the planet.
Absorbed low, released high.
Why can forests cool local climate?
Trees transpire large amounts of water vapour. This transpiration absorbs latent heat from the surroundings, lowering local air temperature.
Transpiration = cooling.
In one sentence: evaporation vs condensation energy change.
Evaporation absorbs latent heat from the surroundings (cooling) whereas condensation releases latent heat to the surroundings (warming).
Absorb vs release.
Why does temperature stay constant during a phase change?
Because energy is used to break or form molecular bonds rather than increasing or decreasing kinetic energy, so temperature does not change.
Bonds, not temperature.
Write a model exam sentence explaining evaporation vs transpiration.
Evaporation is the loss of water vapour from non-living surfaces such as oceans and lakes, whereas transpiration is the loss of water vapour from plants through stomata; both are driven by solar energy and absorb latent heat.
One clear contrast + shared point.
What is the main energy driver of the hydrological cycle?
Solar energy, which powers evaporation and drives energy transfers through phase changes.
Sun powers evaporation.
Link deforestation to warming using latent heat.
Deforestation reduces transpiration and evaporation from vegetation. With less latent heat absorption, less energy is taken from the surroundings, so local cooling decreases and temperatures rise.
Less ET → less cooling.
Which has higher evapotranspiration: a forest or a desert (same rainfall), and why?
A forest, because it has much more vegetation and leaf area (more stomata), so transpiration is far greater than in a desert.
More leaves = more transpiration.
Link deforestation to warming using latent heat.
Deforestation reduces transpiration and evaporation from vegetation. With less latent heat absorption, less energy is taken from the surroundings, so local cooling decreases and temperatures rise.
Less ET → less cooling.
Why does temperature stay constant during a phase change?
Because energy is used to break or form molecular bonds rather than increasing or decreasing kinetic energy, so temperature does not change.
Bonds, not temperature.
Write a model exam sentence explaining evaporation vs transpiration.
Evaporation is the loss of water vapour from non-living surfaces such as oceans and lakes, whereas transpiration is the loss of water vapour from plants through stomata; both are driven by solar energy and absorb latent heat.
One clear contrast + shared point.
What is the main energy driver of the hydrological cycle?
Solar energy, which powers evaporation and drives energy transfers through phase changes.
Sun powers evaporation.
Quick check: evaporation vs condensation energy change.
Evaporation absorbs latent heat; condensation releases latent heat.
Absorb vs release.
Quick check: evaporation vs condensation energy change.
Evaporation absorbs latent heat; condensation releases latent heat.
Absorb vs release.
Which has higher evapotranspiration: a forest or a desert (same rainfall), and why?
A forest, because it has much more vegetation and leaf area (more stomata), so transpiration is far greater than in a desert.
More leaves = more transpiration.
In one sentence: evaporation vs condensation energy change.
Evaporation absorbs latent heat from the surroundings (cooling) whereas condensation releases latent heat to the surroundings (warming).
Absorb vs release.
4.1.220 cards
Why is water described as Earth’s “thermostat”?
Because water absorbs, stores, and redistributes heat, reducing temperature extremes and helping stabilise climate.
Stabilises temperature.
What percentage of Earth’s water is in oceans, and what percentage is freshwater?
About 97% is in oceans (saltwater) and about 3% is freshwater.
97% saltwater.
Why is water described as Earth’s “thermostat”?
Because water absorbs, stores, and redistributes heat, reducing temperature extremes and helping stabilise climate.
Stabilises temperature.
What percentage of Earth’s water is in oceans, and what percentage is freshwater?
About 97% is in oceans (saltwater) and about 3% is freshwater.
97% saltwater.
Define “aquifer”.
An aquifer is an underground rock layer that stores water in pores and cracks.
Underground store.
Explain how high specific heat capacity helps oceans regulate climate.
Water can absorb a lot of heat energy with only a small temperature rise, so oceans act as heat sinks that buffer daily and seasonal temperature changes.
Absorb lots of heat with little change.
Explain how high specific heat capacity helps oceans regulate climate.
Water can absorb a lot of heat energy with only a small temperature rise, so oceans act as heat sinks that buffer daily and seasonal temperature changes.
Absorb lots of heat with little change.
Define “aquifer”.
An aquifer is an underground rock layer that stores water in pores and cracks.
Underground store.
Define “residence time” in a water store.
Residence time is how long water remains in a store before moving to another part of the system.
How long it stays.
How does latent heat transfer regulate climate?
Evaporation absorbs latent heat (cooling) and condensation releases latent heat (warming), moving energy around the atmosphere.
Evap cools, cond warms.
Define “residence time” in a water store.
Residence time is how long water remains in a store before moving to another part of the system.
How long it stays.
How does latent heat transfer regulate climate?
Evaporation absorbs latent heat (cooling) and condensation releases latent heat (warming), moving energy around the atmosphere.
Evap cools, cond warms.
What is the difference between infiltration and percolation?
Infiltration is water soaking into the soil surface. Percolation is water moving downward through soil/rock to groundwater or aquifers.
Into soil vs down to aquifer.
What is the difference between infiltration and percolation?
Infiltration is water soaking into the soil surface. Percolation is water moving downward through soil/rock to groundwater or aquifers.
Into soil vs down to aquifer.
Give one example of how ocean currents affect climate.
Ocean currents redistribute heat from the tropics to higher latitudes; for example, warm currents can raise temperatures in nearby coastal regions.
Move heat poleward.
Give one example of how ocean currents affect climate.
Ocean currents redistribute heat from the tropics to higher latitudes; for example, warm currents can raise temperatures in nearby coastal regions.
Move heat poleward.
Why can groundwater become effectively non-renewable?
If extraction exceeds recharge, aquifers can take centuries to refill, so water can run out within human lifetimes.
Pump faster than refill.
How does albedo link ice/snow to climate regulation?
Ice and snow have high albedo so they reflect more solar radiation (cooling). When ice melts, darker water absorbs more radiation (warming).
White reflects; dark absorbs.
Why can groundwater become effectively non-renewable?
If extraction exceeds recharge, aquifers can take centuries to refill, so water can run out within human lifetimes.
Pump faster than refill.
How does albedo link ice/snow to climate regulation?
Ice and snow have high albedo so they reflect more solar radiation (cooling). When ice melts, darker water absorbs more radiation (warming).
White reflects; dark absorbs.
4.1.320 cards
Define a drainage basin (catchment).
A drainage basin is an area of land where all precipitation drains into a single river system, bounded by a watershed.
One “drain”.
Catchment vs watershed: what’s the difference (IB wording)?
Catchment (drainage basin) is the AREA where water drains to one river. Watershed is the BOUNDARY line between basins.
Area vs boundary.
Catchment vs watershed: what’s the difference (IB wording)?
Catchment (drainage basin) is the AREA where water drains to one river. Watershed is the BOUNDARY line between basins.
Area vs boundary.
Define a drainage basin (catchment).
A drainage basin is an area of land where all precipitation drains into a single river system, bounded by a watershed.
One “drain”.
Name two inputs to a drainage basin system.
Precipitation is the main water input and solar energy drives processes like evapotranspiration.
Rain + sun.
In IB terms, what is a watershed?
A watershed is the boundary line (usually high ground like hills/ridges) that separates two drainage basins.
Boundary line.
Name two inputs to a drainage basin system.
Precipitation is the main water input and solar energy drives processes like evapotranspiration.
Rain + sun.
In IB terms, what is a watershed?
A watershed is the boundary line (usually high ground like hills/ridges) that separates two drainage basins.
Boundary line.
Name three components of a drainage basin system.
Examples include the source, tributaries, confluence, main channel, floodplain, and the mouth.
Source–tributaries–mouth.
Name two outputs from a drainage basin system.
River discharge to the sea/lake and evapotranspiration are key outputs (also abstraction by humans).
Discharge + ET.
Name three components of a drainage basin system.
Examples include the source, tributaries, confluence, main channel, floodplain, and the mouth.
Source–tributaries–mouth.
Name two outputs from a drainage basin system.
River discharge to the sea/lake and evapotranspiration are key outputs (also abstraction by humans).
Discharge + ET.
Is a drainage basin an open or closed system, and why?
At the local scale a drainage basin is an open system: water enters as precipitation and leaves via evapotranspiration and runoff/discharge.
Inputs and outputs.
Define “confluence”.
A confluence is the point where two rivers or streams meet.
Meet point.
Define “confluence”.
A confluence is the point where two rivers or streams meet.
Meet point.
Is a drainage basin an open or closed system, and why?
At the local scale a drainage basin is an open system: water enters as precipitation and leaves via evapotranspiration and runoff/discharge.
Inputs and outputs.
Why must water management consider the whole catchment?
Because activities anywhere in the basin can change flow, sediment, and pollution, affecting ecosystems and people downstream.
Whole system thinking.
Explain why “upstream affects downstream” in a drainage basin.
Water, sediments, and pollutants move through tributaries into the main river, so land use upstream can change flooding, water quality, and ecosystems downstream.
Trace the flow.
Why must water management consider the whole catchment?
Because activities anywhere in the basin can change flow, sediment, and pollution, affecting ecosystems and people downstream.
Whole system thinking.
Explain why “upstream affects downstream” in a drainage basin.
Water, sediments, and pollutants move through tributaries into the main river, so land use upstream can change flooding, water quality, and ecosystems downstream.
Trace the flow.
4.1.420 cards
What property of water helps stabilise temperature, and how?
High specific heat capacity: water absorbs lots of heat with little temperature change, so oceans buffer climate.
Heat sink.
List four ways water regulates climate.
High specific heat capacity, latent heat transfer (evaporation/condensation), ocean currents, water vapour greenhouse effect, and albedo effects of ice/snow.
Give distinct mechanisms.
What property of water helps stabilise temperature, and how?
High specific heat capacity: water absorbs lots of heat with little temperature change, so oceans buffer climate.
Heat sink.
List four ways water regulates climate.
High specific heat capacity, latent heat transfer (evaporation/condensation), ocean currents, water vapour greenhouse effect, and albedo effects of ice/snow.
Give distinct mechanisms.
How can water vapour act as a positive feedback?
Warming increases evaporation, raising atmospheric water vapour, which strengthens the greenhouse effect and causes further warming.
More vapour = more heat trapped.
State the latent heat effect of evaporation and condensation.
Evaporation absorbs heat (cooling). Condensation releases heat (warming).
Absorb vs release.
State the latent heat effect of evaporation and condensation.
Evaporation absorbs heat (cooling). Condensation releases heat (warming).
Absorb vs release.
How can water vapour act as a positive feedback?
Warming increases evaporation, raising atmospheric water vapour, which strengthens the greenhouse effect and causes further warming.
More vapour = more heat trapped.
Why does melting ice often accelerate warming?
Melting reduces surface albedo, exposing darker water/land that absorbs more solar radiation, increasing warming (ice–albedo feedback).
Lower albedo → warmer.
How do ocean currents regulate climate in one sentence?
They move heat from the tropics toward the poles and return cooler water toward lower latitudes, redistributing energy.
Transport heat.
Why does melting ice often accelerate warming?
Melting reduces surface albedo, exposing darker water/land that absorbs more solar radiation, increasing warming (ice–albedo feedback).
Lower albedo → warmer.
How do ocean currents regulate climate in one sentence?
They move heat from the tropics toward the poles and return cooler water toward lower latitudes, redistributing energy.
Transport heat.
Why is water vapour important in climate?
It is a greenhouse gas that traps heat, and it can increase as temperatures rise, strengthening warming feedbacks.
Greenhouse gas.
How do oceans act as carbon sinks, and what is one drawback?
Oceans absorb CO2 from the atmosphere, reducing atmospheric warming, but increased CO2 dissolving can contribute to ocean acidification.
Sink with side effect.
Why is water vapour important in climate?
It is a greenhouse gas that traps heat, and it can increase as temperatures rise, strengthening warming feedbacks.
Greenhouse gas.
How do oceans act as carbon sinks, and what is one drawback?
Oceans absorb CO2 from the atmosphere, reducing atmospheric warming, but increased CO2 dissolving can contribute to ocean acidification.
Sink with side effect.
What’s the best structure for outline questions on climate regulation by water?
Give several distinct mechanisms as separate points (one per sentence), such as specific heat capacity, latent heat transfer, currents, greenhouse effect, and albedo.
One mechanism per sentence.
What’s the best structure for outline questions on climate regulation by water?
Give several distinct mechanisms as separate points (one per sentence), such as specific heat capacity, latent heat transfer, currents, greenhouse effect, and albedo.
One mechanism per sentence.
What is the climate effect of ice and snow, and why?
Ice and snow reflect solar radiation due to high albedo, producing a cooling effect.
High reflectivity.
What is the climate effect of ice and snow, and why?
Ice and snow reflect solar radiation due to high albedo, producing a cooling effect.
High reflectivity.
4.1.520 cards
What does it mean that water is polar?
Water has an uneven charge distribution: oxygen is slightly negative and the hydrogen atoms are slightly positive, creating a dipole.
Uneven charges (dipole).
What is a hydrogen bond in water?
A weak attraction between the slightly positive hydrogen of one water molecule and the slightly negative oxygen of another water molecule.
Weak between molecules.
What is the difference between cohesion and adhesion in water?
Cohesion is attraction between water molecules; adhesion is attraction between water molecules and other surfaces (like soil or plant tissue).
Water-water vs water-surface.
Why is water called an excellent solvent?
Because its polarity allows it to surround and separate ions and other polar molecules, so they dissolve and can be transported.
Polarity helps dissolve ions.
Give one environmental importance of surface tension in water.
Surface tension (from cohesion) supports small organisms at the surface and helps water move through plants via capillary action.
Think: small insects, plants.
Define specific heat capacity.
The energy required to raise the temperature of 1 kg of a substance by 1°C.
Energy to warm 1 kg by 1°C.
Why do oceans moderate coastal climates?
Water has a high specific heat capacity, so oceans heat up and cool down slowly, reducing temperature extremes near coasts.
Slow temperature change.
What is latent heat in the context of water?
Energy absorbed or released during a phase change (melting/evaporation/condensation) without a temperature change.
Phase change energy.
How does evaporation cool the environment?
Evaporation requires energy (latent heat) which is taken from the surroundings, reducing local temperature.
Energy is taken from the surface.
Why is water vapour considered a positive feedback in climate?
Warming increases evaporation, adding more water vapour (a greenhouse gas) which increases warming further.
Warming → more vapour → more warming.
What is water’s density anomaly?
Water is less dense as a solid than as a liquid, so ice floats on liquid water.
Ice floats.
Why does ice floating matter for aquatic ecosystems in winter?
Floating ice forms an insulating layer so water below stays liquid, allowing aquatic organisms to survive.
Insulation effect.
What is the photic zone?
The upper layer of water where light penetrates enough for photosynthesis to occur.
Where photosynthesis happens.
How does turbidity affect aquatic productivity?
Turbidity reduces light penetration, shrinking the photic zone and lowering photosynthesis and primary productivity.
Cloudier water = less light.
Give one link between water clarity and biodiversity.
Clear water allows deeper light penetration, supporting more photosynthetic organisms and often higher biodiversity in the photic zone.
More light supports more life.
What is the main reason water has unique properties?
Hydrogen bonding between polar water molecules causes unusual thermal, density, and solvent properties.
H-bonds drive the properties.
Name two water properties that help regulate climate.
High specific heat capacity and high latent heat (especially during evaporation and condensation).
Heat storage + phase change.
How does water’s polarity support life in ecosystems?
It makes water a solvent for ions and polar molecules, enabling nutrient transport and chemical reactions in organisms.
Solvent for nutrients.
Why is ice floating described as life-saving for lakes?
Because it prevents lakes from freezing solid, keeping liquid water and habitat available below the ice.
Liquid water remains below.
Exam skill: Link water’s properties to an ESS outcome in one sentence.
Hydrogen bonding makes water a stable climate buffer and a life-supporting solvent, shaping ecosystem productivity and survival.
Mechanism → outcome.
Topic 4.1 study notes
Full notes & explanations for Water systems
ESS exam skills
Paper structures, command terms & tips
Want smart review reminders?
Sign up free to track your progress. Our spaced repetition algorithm will tell you exactly which cards to review and when.
Start Free