4B4 Earth's Hydrosphere

Question 1

What are the main properties of water?

Answer 1

• Polarity
• High heat capacity
• Surface tension
• Ability to dissolve substances

These properties make water vital for life and many natural processes.

Question 2

Why is water a polar molecule?

Answer 2

It has a positive and a negative end due to its bent shape.

This polarity allows water to interact with other polar molecules and ions.

Question 3

Why does water have a high specific heat?

Answer 3

It can absorb a lot of heat before changing temperature.

Water’s high specific heat is due to its hydrogen bonds, which absorb heat energy. This allows water to resist temperature changes, helping stabilize temperatures in organisms and ecosystems, making it essential for life on Earth.

Question 4

True or False:

Ice sinks in water because it is denser than liquid water.

Answer 4

False

Ice is less dense than water, causing it to float due to its crystalline structure, which spaces molecules farther apart.

Question 5

Fill in the blank:

The ability of water to climb narrow tubes against gravity is called ________ _______.

Answer 5

capillary action

Capillary action happens because of adhesion (water sticking to the surface) and cohesion (water sticking to itself), allowing water to move upward in narrow spaces.

Question 6

What causes water’s high boiling point?

Answer 6

Hydrogen bonding between water molecules.

Hydrogen bonds between water molecules require a lot of energy to break, which increases its boiling point.

Question 7

What is the water cycle?

Answer 7

The continuous movement of water through Earth’s systems.

The water cycle includes processes like evaporation, condensation, precipitation, and runoff that recycle water on Earth.

Question 8

What are the main processes in the water cycle?

Answer 8

• Evaporation
• Condensation
• Precipitation
• Runoff

These processes work together to maintain Earth’s water distribution and support ecosystems.

Question 9

True or False:

Precipitation is when water vapor turns into liquid or ice.

Answer 9

True

Precipitation includes rain, snow, sleet, and hail, which return water to the Earth’s surface.

Question 10

Fill in the blank:

________ is the process where water vapor in the air cools and forms liquid water.

Answer 10

Condensation

Condensation forms clouds, fog, or dew and is a key step in water returning to Earth’s surface.

Question 11

What is runoff in the water cycle?

Answer 11

The movement of water from land to bodies like rivers, lakes, and oceans.

Runoff occurs after precipitation and plays a role in replenishing water sources.

Question 12

How do plants contribute to the water cycle?

Answer 12

Through transpiration.

Transpiration is when plants release water vapor into the atmosphere, aiding atmospheric moisture.

Question 13

True or False:

Clouds are formed during the process of condensation.

Answer 13

True

As water vapor condenses, tiny droplets of water gather to form clouds.

Question 14

Fill in the blank:

The water cycle is driven by the energy from the ______.

Answer 14

sun

The sun provides the necessary heat for evaporation, which is the starting point for the water cycle.

Question 15

How does snow contribute to the water cycle?

Answer 15

It accumulates in winter, melts in spring, and contributes to runoff.

Snowmelt is a significant water source for many rivers and streams.

Question 16

What is groundwater?

Answer 16

Water beneath Earth’s surface in soil and rock.

Groundwater is a major source of fresh water for wells, springs, and rivers.

Question 17

What is the water table?

Answer 17

The upper surface of the saturated zone of groundwater.

It marks the boundary between the saturated and unsaturated zones in the ground.

Question 18

True or False:

The water table always stays at the same level.

Answer 18

False

The water table can rise or fall depending on precipitation, evaporation, and human activity like groundwater extraction.

Question 19

What is a layer of rock or sediment that holds and transmits water?

Answer 19

Aquifer

Aquifers are underground layers that store and transmit water, often used for wells and springs.

Question 20

What are the primary uses of groundwater?

Answer 20

1. Drinking water
2. Irrigation
3. Industrial use

Groundwater is essential for many human activities, especially in areas without reliable surface water sources.

Question 21

What land area drains water into a specific river or body of water?

Answer 21

Watershed

Watersheds are important for managing water resources, as all the water within a watershed flows to a common outlet.

Question 22

True or False:

A watershed only includes the river itself.

Answer 22

False

A watershed includes all the land and tributaries that drain into the river, including lakes and streams.

Question 23

What is erosion?

Answer 23

The process of rocks and soil being worn away by the flow of water.

Erosion shapes riverbeds, creates valleys, and can lead to the transport of sediment downstream.

Question 24

What is the process by which sediment is dropped or settled by a river?

Answer 24

Deposition

Deposition occurs when the water flow slows down, causing the sediment it carries to settle.

Question 25

# Fill in the blank: A \_\_\_\_\_\_\_ is formed by the **deposition of riverbanks**.

Answer 25

delta ## Footnote **Deltas** are formed by deposition, not erosion, where rivers deposit sediment as they slow down near a body of water.

Question 26

What is a **slow-moving mass of ice** formed by accumulated snow?

Answer 26

Glacier ## Footnote **Glaciers** flow under their own weight and shape landscapes through erosion and deposition.

Question 27

What is the main **difference** between glaciers and ice sheets?

Answer 27

Ice sheets are much **larger** than glaciers and cover vast areas of land. ## Footnote Ice sheets cover entire *continents*, like Antarctica and Greenland, whereas glaciers are smaller and typically found in mountainous regions.

Question 28

# True or False: Glaciers can **only** form in polar regions.

Answer 28

False ## Footnote Glaciers can form in *any region* where snow accumulation exceeds melting, including high mountain ranges near the equator.

Question 29

# Fill in the blank: \_\_\_\_\_\_\_\_ is the **process** by which snow compacts and turns into glacial ice.

Answer 29

Compaction ## Footnote **Compaction** refers to snow compacting under pressure into firn (dense granular snow) before eventually forming glacial ice over time.

Question 30

How does a glacier **move**?

Answer 30

Through **internal deformation** and sliding over the bedrock. ## Footnote The **weight** of the ice causes the glacier to flow, similar to a slow river of ice.

Question 31

# Define: Sea ice

Answer 31

Ice that forms on the **surface of the ocean** from freezing seawater. ## Footnote Sea ice is *thinner* and more dynamic than glaciers and ice sheets and does not contribute to sea level rise when it melts.

Question 32

What is **ocean circulation**?

Answer 32

The **movement of ocean water** driven by wind, temperature, and salinity. ## Footnote This includes *both* surface currents (like the Gulf Stream) and deep-water currents that distribute heat and regulate climate.

Question 33

# True or False: Sea ice **contributes** to rising sea levels when it melts.

Answer 33

False ## Footnote Since sea ice is already floating on the ocean, its melting *does not* raise sea levels, unlike ice sheets or glaciers that are on land.

Question 34

What drives **surface ocean currents**?

Answer 34

1. Wind 2. Earth's rotation ## Footnote The *Coriolis effect* causes the currents to curve, influencing global weather patterns.

Question 35

# True or False: The Gulf Stream is a **warm** ocean current along the North American coast.

Answer 35

True ## Footnote The Gulf Stream *carries* warm water from the Gulf of Mexico to the North Atlantic.

Question 36

What is the movement of ocean water due to **temperature and salinity** called?

Answer 36

Thermohaline circulation ## Footnote *Thermohaline circulation* drives global heat transfer and supports marine ecosystems by moving warm and cold water across the oceans.

Question 37

How does **wind transfer energy** through water?

Answer 37

Waves ## Footnote The size and strength of **waves** depend on the wind’s speed, duration, and the distance over which it blows.

Question 38

What is the **difference** between wave height and wave length?

Answer 38

* **Wave height** is the distance from crest to trough. * **Wave length** is the distance between crests. ## Footnote They are key **factors** in determining a wave's energy and power.

Question 39

What are the main **components** of seawater?

Answer 39

* Water * Dissolved salts ## Footnote The pimary kind of salt is sodium chloride, but it also contains trace amounts of magnesium, calcium, and sulfate.

Question 40

# True or False: Seawater composition is the **same** everywhere in the ocean.

Answer 40

False ## Footnote The composition **varies** by location but is primarily water with dissolved salts.

Question 41

How does **temperature** affect seawater?

Answer 41

Colder water is **denser** than warmer water. ## Footnote The density difference causes the movement of ocean currents and drives the *thermohaline circulation*, which regulates global climate.

Question 42

What is a **natural hazard**?

Answer 42

A natural **event that risks** human health, property, and the environment. ## Footnote Examples include earthquakes, floods, and hurricanes, which can cause significant damage and loss of life.

Question 43

How are hazards **classified**?

Answer 43

1. Natural 2. Human-made ## Footnote *Natural* hazards include earthquakes and hurricanes, while *human-made* hazards include industrial accidents and pollution.

Question 44

# Define: Flooding

Answer 44

The **overflow** of water onto normally dry land. ## Footnote It can occur due to heavy rainfall, storm surges, or dam failures, causing *damage* to property and infrastructure.

Question 45

What is a **storm surge**?

Answer 45

A **rise in sea level** caused by strong winds from a storm. ## Footnote It can lead to *coastal flooding* and damage, especially during hurricanes or typhoons.

Question 46

# True or False: Flooding is caused **only** by heavy rainfall.

Answer 46

False ## Footnote **Flooding** can also result from storm surges, snowmelt, or dam failures, not just rain.

Question 47

# Fill in the blank: \_\_\_\_\_\_\_\_ occur when the ground collapses, forming a **depression**.

Answer 47

Sinkholes ## Footnote This *hazard* can occur suddenly and cause significant damage, especially in areas with soluble bedrock.

Question 48

Why are sinkholes more **common** in limestone areas?

Answer 48

Limestone dissolves in water, creating **underground cavities**. ## Footnote As the cavities grow larger, the surface layer may collapse, forming a *sinkhole*.

Question 49

# True or False: Flooding can occur in **deserts**.

Answer 49

True ## Footnote *Flash floods* in desert regions occur due to sudden, intense rainfall that the dry ground cannot absorb quickly.

Question 50

What are the long-term **effects** of sea-level rise on coastal ecosystems?

Answer 50

It can **destroy** habitats and cause biodiversity loss. ## Footnote Rising water levels can also cause saltwater intrusion into freshwater systems.