objectives: › describe the amount of fresh water on earth › relate the structure of water...
TRANSCRIPT
Fresh WaterChapter 14
Section 1 Water and Its Properties
Objectives:› Describe the amount of fresh water
on earth› Relate the structure of water
molecules to the physical and chemical properties of water
› Explain why living things need water› Generalize about the role of energy
in the water cycle
Skills Warm-up
Down the Drain› How much water do you use in a
day?› Use the following estimates in your
calculations: Toilet – 20L/flush Glass of water – 0.25L Faucet – 15L/min 5-minute shower – 75L
Earth’s Fresh Water Earth is the water
planet – ________ of surface covered by water
Total Water:› ________ salt water› ________ fresh water in
glaciers/ice caps› ________ water is
underground› _____ is in atmosphere› Whatever is left -
surface fresh water
Put it in Perspective
Imagine ___________ of soda – represents all of earth’s water
Now imagine _______ of soda – represents the amount of usable fresh water
We must protect and conserve !
Properties of Water 3 Phases of Matter ________ – has its own
shape because molecules are held together rigidly
_______ – takes shape of container because molecules not held together as closely
____ – fills its container because molecules not held together
Properties of Water
Water is the only compound that occurs in all 3 ______ ___ _______ at ________ earth temperatures
Ice covered lake› Ice is water’s solid
phase› Water underneath is
the liquid phase› Water vapor above
ice is the gas phase
Water Molecule
Water’s chemical formula is _______
What does that mean?
Water is a _________ molecule – the hydrogen atoms have a slight __________ charge and the oxygen a slight __________ charge
Water Molecule
Since opposites attract:
The ___________ atoms from one water molecule are
Attracted to the __________ atoms from other water molecules
They “stick” together through ___________ __________
Physical Properties of Water
Water gains and loses heat energy _________ compared to other compounds
Heat is the energy of ___________ molecules
It takes ________ energy to separate polar water molecules and get them moving
Water also ________ ______
Physical Properties of Water Normally a
material’s solid phase is _______ than its liquid phase
But, water’s solid phase is ____ _______
This is because water’s polar molecules can’t get too close together
Like charges _______ That is why ice
______ on water
Physical Properties of Water
Water has ________ _______ – its surface is a skin-like layer
This occurs because water molecules _________ each other
Gives water droplets a __________ shape
Also causes light objects to ________
Chemical Properties of Water Water is called the
_______________________ It can dissolve many
other _____ substances Think of all the things
you drink (milk, lemonade, soda) that are mixtures of other things in water
This is also due to water molecules’ ______ – they attract other things and keep them in solution
Activity
Water Lab
Water Cycle The water cycle is a
_________________ of evaporation and condensation that controls the distribution of the earth's water as it:
____________ from bodies of water
____________ ____________ ____________ to those
bodies of water
Water Cycle _____________ – water
vapor condenses into liquid water
_____________ – liquid water is heated by sun’s energy to form water vapor
_____________ – Water falls as rain, hail, sleet, or snow
________ – when water cannot soak into the ground – gravity pulls it downhill
Water and Living Things
_________ is essential for all living things
About _______ of your body weight is from water
You can survive ______ without food than without water› 3-5 days without
water› Several weeks
without food
Water and Living Things
We take in water by ________ and ________
We release water in _____________, _____________, _____________, etc.
Water keeps us cool on hot days – heat energy from your hot skin evaporates watery sweat, cooling you off
Water and Living Things ______ use water, along
with carbon dioxide and light from the sun for ____________________
_____________ – process by which water move up through a plant eventually exiting through tiny __________ in their leaves
_______ __________ of water return to the atmosphere by transpiration
Your Water Use On average, each person in U.S. uses
__________ of water/day – not including indirect uses
Your Water Use
If you include all indirect water uses – the average consumption is over ___________________
Indirect water use can include:› 200,000L to ____________› 800L to ________________› 500L to ________________› 4,000L to ______________
Your Water Use
Where does fresh water come from?› __________________› __________________› __________________› __________________› __________________
All of these sources get their water from precipitation
How Do We Return Water
Water from crops and plants – direct ___________________
Waste water from homes/businesses – must first go through a _____________ __________› _____________– septic
tank separates out wastes from clean water
› _____________ – pipes to sewage treatment plant where water is filtered and cleaned
Activity
Discovery Education “Water Cycle Movie”
Review Questions
1. Describe in your own words what fresh water is. How much of the earth’s water is fresh water?
2. Explain how the structures of a water molecule relates to three properties of water.
3. Write a general statement describing the role of the sun’s energy in the water cycle.
4. Draw and label a diagram that traces the path of a water molecule through the water cycle.
Section 2 Surface Water
Objectives:› Describe three ways in which fresh
water exists on the surface of the earth
› Describe a water shed and its drainage systems
› Predict what life on earth might be like if freshwater didn’t accumulate on earth’s surface
Skills Warm-up
Rain Tracks› Based on your observations, what
happens to rainfall that falls on buildings where you live?
› What could happen that might change the path of the rainwater?
Different Landscapes
Some areas are forests, some are deserts
Areas are different because of the ___________ __ ____________ there
The amount of water in an area depends on the amount of ______________________
Running Water
Water from rain or melted snow can ______ into ground, ____________, or flow over as _________
Runoff forms rills and gullies to flow into streams and rivers
Running water carries water back to _______ and lets water evaporate into air
Streams and Rivers
Streams flow into rivers and rivers flow into oceans forming a _____________________
From above, a drainage system can form a tree-like pattern
______________ – a small stream that flows into a larger one
____________ drainage systems have many tributaries
Streams and Rivers
Rivers give fresh __________________
Rivers transport __________________
Land along riverbanks is good for ____________ because there is plenty of water and nutrient-rich soil
Watersheds The surrounding land area that supplies ______ to the streams of a drainage system
Can be less than 1 km to thousands of km
Watersheds that supply runoff to different drainage systems are separated by a ridge called a _____________
Rocky Mountains make up the _______________ ______________________› Streams to the _______
drain to the Atlantic Ocean› Streams to the _______
drain to the Pacific Ocean
Standing Water When running water
reaches a low area in a drainage system, it stops flowing
This low area fills with water to become› ________ – form in large,
deep depressions – sunlight doesn’t reach bottom
› ________ – form in small depressions – sunlight reaches bottom
› ________ – artificial lake built to store fresh water or prevent flooding
Frozen Water
Most of the world’s fresh water is _________
Near the poles, permanent __________ form
Snowfields turn into _____________
During short summers, some of the ice _______ supplying fresh water to many areas
The Wandering River
___________ River is the 3rd longest in the world – has >200 tributaries and 4th largest watershed
It hasn’t always been in the _______________
About every _________ years it changes course, cutting a new ____________ and abandoning its old one
The Wandering River
In Louisiana, the Mississippi has been trying to change its course __________ to the Atchafalaya River
If this happened, the port of ____________ would dry up and the cities near the Atchafalaya would flood
The army corps of engineers began a huge flood-control project
Review Questions
1. What are three ways in which fresh water exists on the earth’s surface?
2. Describe a watershed and drainage system.
3. What do you think life on earth would be like if there were ne fresh water on the surface?
Section 3 Water Beneath the Surface
Objectives:› Explain what forms groundwater
and describe groundwater zones› Describe the movements and
activities of groundwater› Predict changes in groundwater› Classify earth materials by
permeability
Skills Warm-up
Taking in Water› What happens when you water a
potted plant?› Where does the water go?› On a global scale, a huge amount of
precipitation soaks into the ground.› The amount of water underground is
more than all the world’s rivers and lakes combined.
Groundwater The water that _______
into the ground from _______ or melted _____
Groundwater fills in the _____ ________ between dirt and rock particles
_________ – the % of a material’s volume that is pore space
Materials with high porosity can hold _________
Permeability
If pore spaces are well connected, water flows easily through the rock – it is ______________
Permeable rocks› ___________› ___________› ___________
Impermeable rocks› ___________› ___________
Groundwater Zones
Water from rain or snow soaks into the ground – _________ pulls it down
Once the water reaches an impermeable layer it must __________ _____
When the water can’t spread out any further, the water level __________
Groundwater Zones
Groundwater creates two distinct zones
___________________ – lower - all pore spaces contain water
___________________ – higher – all pore spaces contain air
_____________ ___– the boundary line between the two zones
Things That Affect Water Table
_____________________› After lots of rain the
water table is higher› After a dry spell
water table is lower ______________________
______________________› Impermeable layer
close to surface – water table is higher
› Impermeable layer deeper – water table is lower
Moving Groundwater __________ – a layer of
permeable rock or sediment containing groundwater
Usually form in sandstone, sand, or gravel – above or between impermeable rock layers
Have a _______________ – exposed area where water soaks in
______________ Aquifer – largest in the U.S. – from South Dakota to Texas
Moving Groundwater
Aquifers are important sources of ______ _____
People _____ ______ into the zone of saturation and ________ water out
An _____________ gets water from an opening in a slanted, capped aquifer
Water is forced to the surface by pressure from the aquifer
Moving Groundwater
CO2 in air combines with water to form __________ _________
Acidic rainwater chemically reacts with some rocks forming _______ and __________
If water evaporates on ceiling – icicle-like ______________ form
If water evaporates on floor – pillars of minerals or ______________ form
Moving Groundwater
Groundwater can be heated by contact with: › _______________(western
U.S.)› _______________________
(eastern U.S.) ______________ – any body of
water with a temperature higher than the human body’s
___________ – a fountain of hot water ejected from the ground by superheated steam in underground chambers
Protecting Groundwater
Water is the __________ __________
As rainwater travels through materials above ground – it dissolves ___________
If the dissolved substances are harmful – the groundwater becomes ___________
Protecting Groundwater
Old landfills and dumps are a major hazard to groundwater
As rainfall moves through it dissolves chemicals in paints, cleansers, household and industrial wastes
Protecting Groundwater
_____ _________ have a lining of ______________ clay, asphalt, or plastic
Water containing dissolved chemicals can’t soak through this layer into the ground
After landfill is full, it is __________ with another impermeable layer
Groundwater is then __________ from pollution
Review Questions
1. What is groundwater? Describe two distinct groundwater zones.
2. Describe three movements and activities of groundwater.
3. What will happen to the water table in an area during a prolonged drought? What else could affect the water table the same way?
4. Order the following from least to most permeable: gravel, sand, clay, sandstone.
Lab Activity
How are a siphon and an artesian well similar?
Page 334 in textbook
Activity
Groundwater Webquest
techalive.mtu.edu/meec/module04/title.htm
Test Review
Read Chapter 14 review – page 335 and complete:
› Check Your Vocabulary› Check Your Knowledge