PARENT DOCENT GUIDE
HELPING HANDS SCIENCE
5
MATTOS ELEMENTARY
SCIENCE MAGNET SCHOOL
Fifth Grade
How can you determine the water quality of a fresh water
pond?
Math Science Nucleus
2015-16
1 CLASS PROJECT
FIFTH GRADE
5 QUESTION: How do you determine the water quality of a fresh water
pond?
BACKGROUND: Water is an important resource for humans. Natural
ponds have turned into areas where storm water can go to prevent
flooding. However, pollutants from the surrounding area can enter the water through
run off. Monitoring the help of a pond can help determine if there will be problems.
PRIOR RESEARCH FOR CLASS: What kind of pollution is in our waterways? How
does water flow in Fremont?
EXPERIMENTAL DESIGN: Monitoring for pH can help scientists determine if
something is wrong with the water supply. Collecting data at several points can help
determine if the water is poor or good.
The fifth grade has 2 projects:
1. Long term monitoring of a pH tank that has been “polluted” and try to determine
if tule plants help to “bioremediate” the tank over time. Another tank will be one
with tule and algae that acts as a control.
2. Data points at Tule Ponds and looking at the pH and recording the information in
data booklets.
DOCENT GUIDELINES
DURATION: 50-60 minutes
GENERAL INFORMATION: Do not spend more than 10-15 minutes for an introduction and
instructions. Allow as much time for the hands on component. If you are doing an art project,
make sure you have all the materials readily available.
If you are teaching a new concept to fifth graders make sure they understand some of the
vocabulary. You may need to repeat large words and have students repeat the word. Leave
about 5 minutes to discuss what they did in the lab and urge them to develop a summary or
conclusion of what they learned.
Note: Background information is added information for the docent only.
2 FIFTH GRADE
G
TEACHE
ER LESSO
ON
LOCAL WATERSH
HEDS
5
TIVE:
OBJECT
Designin
ng an experriment that tests wheth
her tules ca
an clean hig
gh basic water.
MATER
RIALS:
PROCEDURE:
1. Per group.
g
Chop
p the cabba
age into sm
mall pieces a
and put in 4
400 ml beaker. Place
about 25
50 ml of boiling water and mix. When wate
er has a strrong purple color the
solution is ready. Cool
C
before
e using. File
er out the p
plant material to obtain
n a red-purp
pleolored liquid
d. This liqu
uid is aboutt a pH 7.
bluish co
Here is a table of approxima
a
te colors of
o red cabba
age indicattor solution
n at differe
ent
pH's. If you wish, make yourr own chart, using ch
hemicals off known pH
H.
pH
p
2
4
6
8
10
1
12
Co
olor
Red
Purple
Violet
Blue
Blue-Green
Greenis
sh Yellow
1. Use a test tube that can ho
old about 15
1 ml of liqu
uid. Put in 7 ml of watter per 10 ttest
tubes.
2. Put in
n about 4 ml
m of solution
n per test tu
ube. Label the test tub
be by placin
ng a piece of
paper in
n front of the
e test tube with the solution that yyou will putt in each of the test tub
bes.
You can
n use baking
g soda (sod
dium bicarb
bonate) , vin
negar (acettic acid), ble
each,
ammonia, lemon ju
uice, mouth wash, crea
am of tartarr (potassium
m bitartrate
e), lye
(potassium hydroxiide) any solution that your
y
instrucctor provide
es.
3 3.Use your red cabbage indicator solution and put in drops of the solution until there
is a color change. Match the color with the color scheme above and figure out the
pH of the solution. See if you can rearrange the test tubes to go from acidic to basic.
DATA SHEET
Date
Tank A
pH Temp
4 Tank B
pH
Temp
FIFTH GRADE-LESSON 1
LOCAL WATERSHEDS
5
OBJECTIVES:


Looking at local watershed.
Creating a watershed.
VOCABULARY:



watershed
storm water
water supply
MATERIALS:
 map of Tri-City
 Local Watershed http://msnucleus.org/watersheds/index.html
 Shape it
 Plastic spoons, knives or other items to help create a watershed
BACKGROUND:
Wetlands can be various sizes and shapes, with either freshwater, brackish water, or
marine water for a portion or an entire year. Marshy, boggy, or swampy areas also
qualify as wetlands.
There are three indicators of wetlands that include the presence of water, soil
development under aquatic conditions, and the presence of wetland plants. Water can
be caused by run-off or ground water and is available during the growing season.
Wetlands are important for biological life because it sustains a diversity of organisms
throughout the year. Wetlands provide rest stops for migrating animals like birds.
Wetlands also filter and clean storm water from pollutants. Different wetlands fill
different functions in an ecosystem. Tyson Lagoon is a permanent, freshwater wetland,
whereas the other areas that contain water only during the rainy season are considered
seasonal wetlands.
Watersheds naturally clean themselves as water can be filtered as it flows through
wetlands. Water that migrates through the different levels of the watershed nourishes
biological life. However, we sometimes pollute these wetlands by discharging industrial
or municipal waste into the watershed (point source pollution). This overloads the
system and pollution of toxic substances may increases. Even small amounts of
pollution (non point pollution) can accumulate and cause significant damage. Our
watersheds reflect the health of our environment.
5 PROCEDURE:
w students the
t local
1. Show
waterrshed map and see if the
t
stude
ents can rec
cognize the
e
differe
ent areas.
(http:///msnucleus.org/waterrshe
ds/ind
dex.html)
d out the pla
acemat of th
he
2. Hand
Tricity
y Area. Ask the stude
ents
to find
d the follow
wing places,, by
puttin
ng their finger. Walk around
a
and check that they correcctly have fo
ound
the arreas.
a. citties of Newark, Fremo
ont, Union C
City
b. as
sk them wha
at is the diffference bettween the b
brown, lightt blue and d
dark
blue lines
l
on the
e map (make sure the
ey see the le
egend). Th
he brown are
sewage line, the
e dark blue represent sstorm drain
ns, pipes, an
nd natural
waterr movement; the light blue
b
is drin king water
c. Fiind East, West,
W
North,, South (ea
ast is where
e the East B
Bay Hills arre,
Mission Peak)
d. ho
ow does the
e water flow
w
e. loc
cate: Tule Ponds and Lake Eliza
abeth
f. outtline the Mo
owry Slough Watershe
ed, Laguna Creek Wattershed, an
nd
Alameda Creek Watershed
d
6 3. Use
U the Watter Slidesho
ow to go ov
ver the impo
ortance of w
water, assu
uring studen
nts
th
hey will learrn more abo
out water th
hroughout tthe year. G
Go quickly tthrough the
e
slides (emph
hasis just th
hat water is
s universal ssolvent (evverything disssolves in it)
ong molecule. It can cut
c through soil and roccks over tim
me. Water
and is a stro
however is a master to
o gravity. Itt flows dow
wnhill and crreates enou
ugh energy to
undercut part of the earth’s surfac
ce (erosion)).
Stop
S
at page
e 6 and sho
ow students
s the patterrn of water fflowing dow
wnhill. On tthe
placemat yo
ou can see the
t pattern by the can
nyons from Mission Pe
eak area to the
flatland.
Hand
H
out the
e shape it trays so students can ccreate theirr own waterrshed. Idea
ally
2 -3 students can work on a projec
ct. Studentts should p
produce som
mething tha
at is
hilling and fo
orms a netw
work of stre
eams (calle
ed dendriticc pattern). T
The watersshed
is
s defined as
s gravity ac
cting on an area to brin
ng all the w
water and de
ebris
downward.
7 FIFTH GRADE - LESSON 2
ELEMENTS, COMPOUNDS AND POLLUTANTS
OBJECTIVES:


5
Using the periodic table
Exploring two elements that form a compound.
VOCABULARY:





compound
element
atom
halite
molecule
MATERIALS:




Rock Cycle Slideshow
Periodic table
5 sets of elements and compounds
Sets of pollutants
BACKGROUND:
Elements are composed of small particles called atoms. Atoms are the smallest units of
an element that can combine with other elements. Atoms of different elements combine
to form compounds. Baking soda (sodium bicarbonate), for example, is made of
sodium, hydrogen, carbon, and oxygen. Hydrogen gas, composed of two hydrogen
atoms is technically a compound. The chemical formula of a compound lists all the
elements that make up the compound and their proportions. The smallest unit of a
compound is a molecule.
A physical property of an element or compound is any characteristic that can be
observed such as color, odor, density, hardness, or melting point. A chemical property
refers to the chemical composition of that substance. For example, silicon (Si) and
oxygen (O) make up quartz, silicon dioxide (SiO2). A physical change occurs when a
compound changes state, for example, ice melting to form water. No new elements or
compounds are formed. Physical changes require no modification of the internal
molecular arrangement of the compound.
Minerals are either composed of one type of element (a native mineral) or two or more
elements (a compound). The characteristics of minerals depend on their constituent
Rock Cycle. Table salt (the mineral halite) would not have the same properties if either
sodium or chlorine were replaced with another element such as silver or potassium.
8 However, the characteristics of elements are not always expressed in minerals; for
example, quartz, a hard, glassy mineral, is composed of silicon, which is a lightweight,
metallic element, and oxygen, a clear gas.
A compound consists of two or more
different types of atoms that are chemically bonded. Halite, composed of sodium and
chlorine, is an example. Electrons move around the nucleus of an element in specific
and set orbitals. There are a finite number of electrons in each of these orbitals.
If an atom does not have the full number of electrons in each orbital, it seeks a partner
that can "loan" one or more electrons to "fill" its molecular orbital. This is the essential
cause of chemical bonding. For example, a sodium ion, which has a positive charge
wants to give up an electron whereas a chlorine ion, which has a negative charge wants
to accept an electron. The two elements combine to form an ionic bond (bond formed by
the attraction of unlike charges) and thus form the compound, halite. There are several
additional types of bonding of molecular orbitals which students will learn in high
school.
The type of bonding between atoms and the characteristics of those atoms determines
to a large degree how a compound will "appear" when the atoms combine. In halite, the
chlorine atom is twice the size of the sodium atom. When the chlorine atoms "nestle"
into a "packed" position, the sodium atoms fill in the gaps. This packed position has a
cubic structure, which is reflected in the cubic nature of halite. You can demonstrate this
by placing small and large plastic beads in a small, cubic, clear, plastic box. Shake the
box. If one bead is twice the size of the other, they will pack in a cubic pattern. The large
beads represent chlorine (Cl) atoms and the smaller beads represent sodium (Na)
atoms.
PROCEDURE:
Review Minerals and Periodic table.
Activity 1: Periodic table (elements and compounds). The periodic table lists the
elements in order of increasing atomic number. Each element is described by its name,
atomic weight, atomic symbol, and atomic number. Elements with similar characteristics
are listed in vertical groups called families. The atomic number refers to the number of
protons per atomic nucleus. Atomic mass (weight on many periodic tables) is the
combined mass of the protons and neutrons. You can subtract the atomic number from
the atomic mass and find the number of neutrons.
1. Go over slides 1-4 from Rock Cycle slideshow.On the periodic table placemats
have students find the following elements that are used in daily language:
calcium; silicon; iron; zinc; copper. Be sure to have them say what the symbol
and atomic number are and something they are used for (Calcium-bone health;
silicon-computer chips; zinc-immunity; copper-wiring).
9 2. Go over slides 4-8 from the Rock Cycle slideshow. Talk about some of the
physical properties of common compounds such as water and sodium chloride.
3. Hand out the different elements and compounds and ask the students to identify
the atomic number and symbol. The set that Mattos has is the following:
Elements: Magnesium (Mg), Sulfur (S), Aluminum (Al), Antimony (Sb) and Zinc
(Zn). Have them also describe properties, especially color.
Compounds: Potassium bichromate (K2Cr2O7; Manganese dioxide (MnO2,
Sodium thiosulfate (Na2S3O3 (H2O); Antimony sulfate (Sb2(SO4)3; Calcium
chloride (CaCl2)
4. Use the worksheet and periodic table placemat to identify sources of heavy
metals that we might find at Tule Ponds. Go over the following and have
students answer the questions as a group.
a. Define a watershed
b. Circle and label Tyson Lagoon, Mowry Slough, Laguna Creek, and
Alameda Creek Watersheds.
c. List the elements found in stormwater that originates from different modes
of transportation. Find the answers in the small containers.
Source
Cd
Co
Cu
Fe
Gasoline
Exhaust
Motor
Oil/Grease
Antifreeze
Brake Lining
Rubber
Asphalt and
Concrete
Engine Wear
10 Mn
Ni
Pb
Zn
SOURCES OF HEAVY METALS FROM TRANSPORTATION Source
Cd
d
Co
Gasoline
Exhaust
Motor
e
Oil/Grease
Antifreeze
e
Brake Liniing
Rubber
Asphalt an
nd
Concrete
Engine We
ear
11 C
Cu
Fe
Mn
N
Ni
Pb
Zn
FIFTH GRADE - LESSON 3
CONSTRUCTED WETLANDS
OBJECTIVES:


Observe how aquatic plants can clean water.
Learning that you can design an environment
to work in a city.
5
VOCABULARY:



Constructed wetlands
Natural wetlands
Bioremediation
MATERIALS: 


Tules
Microscope
Wetland in the City
BACKGROUND:
Tyson Lagoon was expanded to increase storm water capacity and enhance the
natural habitat of this area. The Public Works Agency of the County of Alameda has
created three ponds (constructed wetlands) which are referred to as Tule Ponds.
Wetlands are among the most productive ecosystems in the world. A fresh water
marsh is as productive as a tropical rain forest. Wetland plants are specialized
because they can withstand water levels that most land plants cannot. Bacteria,
protozoa, and fungi are bountiful as decomposition of organic matter releases
nutrients. These microscopic critters are eaten by larger invertebrates like arthropods
and mollusks, that in turn are eaten by amphibians, reptiles and fish.
During a storm event, water will flow from asphalt, cement, and saturated soil.
Sediments, chemicals, and trash within the watershed, will be mixed with the water.
Ponds B and C use narrow connections to help retard the flow of objects that float, like
oil and garbage. Motor oil coats fish gills, preventing the fish to use dissolved oxygen
in the water. You can notice that the constrictions between the ponds help to narrow
the flow and trap these lighter objects.
Pond A is designed to slow the flow of water, which allows suspended particles to
drop out of the water column. This increases the water quality of the water and is less
of a potential hazard when it enters the San Francisco Bay. The suspended particles
can include heavy metals like copper (Cu), lead (Pb), and zinc (Zn), as well as simple
12 particles like sediment and soil. Tules help to remove them from the water.
Residential and urban growth in a watershed increases water runoff. When you
construct a home, industry or road, water is then prevented from percolating
downwards into the ground and flows into a series of pipes. If you look at the
beginning of Pond A you will see a large pipe which is bringing run-off from the
surrounding community into this stormwater detention system.
Water quality is frequently enhanced as water passes through wetlands. Plants help to
slow the flow of water and cause sediment to settle out. Aquatic plants like algae or
diatoms together with large emergent plants like tules and cattails, add dissolved
oxygen in the water during photosynthesis. Dissolved oxygen is used by fish and other
aquatic organisms. Cattails and tules also provide shelter for larger animals living in the
pond. Bioremediation is a waste management technique that involves the use of
organisms to remove or neutralize pollutants from a contaminated site. [
PROCEDURE:
1. Discuss that Tule Ponds at Tyson Lagoon was created to clean water
before it goes into the San Francisco Bay.
2. Read Wetland in the City, which goes over how the area was created
(based on a real engineer who designed it)
3. Discuss with students some of containments in storm water
Category
Examples
Metals
zinc, cadmium, copper, chromium, arsenic,
lead
Organic chemicals
pesticides, oil, gasoline, grease
Pathogens
viruses, bacteria, protozoa
Nutrients
nitrogen, phosphorus
Biochemical oxygen
demand (BOD)
grass clippings, fallen leaves,
hydrocarbons, human, and animal waste
Sediment
sand, soil, and silt
Salts
sodium chloride, calcium chloride
13 Bring pieces of tule, cattails and hydric (wetland) soil. Hydric soil is
porous and also helps to filter water through microbial action. Have the
students look at the specimens and describe the materials.
Water quality is frequently enhanced as water passes through wetland.
Plants help to slow the flow of surface run off and cause sediment to
settle out. Living aquatic plants like algae and large emergent plants like
tules and cattails, add dissolved oxygen to water during photosynthesis.
Wetland plants support much of the life in open water, and plants like
cattails and tules provide shelter for larger animals living in the pond.
14 What is
s a wetla
and?
Wetlandss come in ma
any shapes and
a sizes. Different typees of wetlandds have diffeerent functioons in
an ecosysstem.
Three thinggs wetlands hhave in comm
mon
1. Watter (surface oor ground)
2. Wettland soil (foormed with w
water called hydric)
3. Wettland plants (plants that can be subm
merged)
Trace the flow of waterr from the maain storm draain. Also note the other sto
orm drains byy a star. .
desscribe
soil
Plantts (cattails)
Pla
ants (tule)
15 FIFTH GRADE – LESSON 4
POLLUTED, DIRTY AND CLEAN WATER
OBJECTIVES:


5
Distinguishing polluted, dirty, and clean water.
Using the microscope to test samples of water.
VOCABULARY:



dissolve
pollute
sediment
MATERIALS: 










sand
food coloring
oil
soap
salt
Swift GH microscope
slides
jars with lids or containers with stirring rod
eyedropper
beakers
Nu, You and Water by J. Blueford
BACKGROUND:
Water is an important resource for all people in the world. People can die from lack of
clean water to drink. Most students do not think about water because in the United
States it is almost an unwritten rule that cities, counties, states and the federal
government will provide this resource. Early in our country this was not so. Many
people died because the rain did not bring water or that sewage from a city polluted the
waterways. The United States is aware of the dangers of polluted water and have one
of the strictest laws in the world. Not all nations in this world have water privileges that
Americans have.
The world’s oceans have always been a “dumping” ground for pollution. In many areas
raw sewage and other wastes are put into the oceans. Many humans see the oceans
as such a vast place that it could never get polluted. But this is wrong. Currents in the
oceans move the pollution away from the land, but it still remains in the system. Some
wastes are sometimes used by plants and animals in the oceans to help them grow, but
too much will upset the natural balance.
16 There are some substances that will dissolve and others that will remain in the system.
For instance, plastic will not degrade and remains floating on the world’s oceans. Other
substances like phosphorous (from soaps) can be used by small plants in the oceans as
fertilizer.
Pollution is a term used by the media and general public frequently. However, most
children do not understand how the word differs from dirty. Pollution is when water (or
any other part of the environment) becomes offensive or harmful to organisms. Fresh
and salt water can become polluted. However, seawater is not polluted just because it is
salty.
Salt water, although not useful to drink by humans, is not polluted or dirty; it has mineral
salts dissolved in it. This lab has the students think about the difference between dirty,
polluted, and clean water.
PROCEDURE:
1. Read “Nu, You and Water”.
2. Brainstorm with students and make a list of polluted and dirty components
of water.
POLLUTED: oil, harmful chemicals (like mercury, lead), too many dead
animals, plastic bags, metal
DIRTY: wood, mud, rocks, algae (kelp)
3. Each group of students should have two jars for Exercise I. Students
should fill up each jar with 50 ml of water and mix one with 25 ml of
vinegar and the other with 2 ml of sand. Students should shake the
jars and determine which jar is dirty or polluted. The sand jar is dirty
because the sand will settle out, however, the vinegar cannot be removed
easily and the solution is therefore polluted.
4. Pre-mix 5 containers (baby food jars work well) and have students look at
one or two drops of each of the containers under the microscope. You
may want to label each jar as UNKNOWN 1, UNKNOWN 2, etc. Below are
suggested contents:
jar 1 = 1/4 water + soil
jar 2 = 1/4 water + 2 drops of food coloring
jar 3 = 1/4 water + 3 drops of oil
jar 4 = 1/4 water + 3 drops of soap
jar 5 = 1/4 water + salt
5. Students should figure out if the water is polluted or dirty and record the
observations on the sheet. Use the microscope to look at a drop of each of
17 the water to see if students can identify particles in the water. You must
remember that polluted or dirty water sometimes depends on the type of
animal using that water. What may not be toxic to humans, may be toxic
to little animals, or vice versa. For instance, soap in water is not polluted if
we wash our face, but if we had to drink soapy water it would be polluted.
Students should be encouraged to justify their answers. Consider it
correct if their justification is logical.
18 LAB SHEET
POLLUTION, DIRTY AND CLEAN WATER
PROBLEM: What is the difference between dirty, clean, and polluted water?
PREDICTION:
EXERCISE I
Listen to the instructions from your teacher.
Which jars of water is dirty?
Which jars of water is polluted?
Why?
EXERCISE II
Look under the microscope at the samples of water. Record if you think they are
polluted or dirty.
SAMPLE #
COMMENTS
1
2
3
4
5
CONCLUSION: The difference between dirty water, clean water, and polluted
water is:
19 5
FIFTH GRADE – LESSON 5
SOLVENTS AND SOLUTES
OBJECTIVES:


Comparing fresh and salt water.
Distinguishing solvents and solutes
VOCABULARY:









clean
dirty
dissolved
fresh
polluted
salty
sediments
solution
solvent
MATERIALS:
 Beakers
 Measuring spoons
 Stirrer
 Salt, sand, sugar, baking soda, Epsom salt, mud, warm and cool water
 Water Slideshow
BACKGROUND:
Water is a universal solvent which means it can dissolve many other substances within
the molecular structure of water. Water becomes salty because many different
components that erode from the land will dissolve and become part of the water. Over
eons of time the water cycle evaporates only fresh water, leaving the “salts” behind.
The term solution means a system in which one or more substances are uniformly
mixed or dissolved in another substance. A solution has two components, a solute and
a solvent. The solute is the substance that is dissolved. The solvent is the substance
doing the dissolving. A solute plus a solvent equals a solution.
Water is considered a universal solvent, in other words, many other substances can be
dissolved into water. Seawater is an example, it contains many ions of dissolved
elements like sodium, chlorine, bromine, calcium, carbon, and many more. Seawater
starts as fresh water but as water falls on the land causing the erosion of rocks,
minerals become a part of the water, and then become part of seawater. Salt water is
20 neither dirty nor polluted, it is a solution that is clean, unless polluted by humans or
nature.
The students should remember that the hydrogen and oxygen "bond" together, or "hold
hands." The bond is very strong and is called a covalent bond. Because the bond is so
strong, water is considered a universal solvent, since many things dissolve in it. Water
is a special type of covalent bond called a hydrogen bond. Salts on the other hand hold
hands very weakly and break up very easily in water. This is called an ionic bond.
The break up of salts in water causes the water to have the ions of that salt. For
instance, table salt is sodium chloride (NaCl). When it is dissolved in water it turns into
a positive ion of sodium (Na+) and a negative ion of chlorine (Cl-). Dissolving does not
mean that the compound breaks into its elements. If that was the case, sodium, the
element is reactive with water and chlorine is a deadly gas. It is important to use the
correct terms early in a student’s education, so they don't get confused later on.
PROCEDURE:
1. Ask students if a body of salt water were to evaporate, would anything be
left. If the students debate over this you might want to set out a dish of
salt water and a dish of fresh water and have them observe what happens
when the water evaporates.
2. In this lab, the students will measure all the correct amounts and follow the
lab sheet. Have them describe what happens when they mix the
materials. Once the students record their findings on one item, have them
clean out the dish and proceed to the next item. Do not dispose of the
sand and mud in the sink. You may want to save the sand and dry it out,
to be used again.
3. Students may ask you why the oceans aren't sweet. The oceans are not
sweet because sugar does not dissolve as fast as salt and does not stay
dissolved. Sugar has strong bonds (covalent) whereby salts have weak
bonds(ionic). Also, salts are much more abundant in the rocks. Have you
ever tasted a sweet rock?
21 PROBLEM: Does temperature of water have anything to do with dissolving
substances?
PREDICTION:
PROCEDURE:
MATERIALS: salt, sand, sugar, baking soda, epsom salt, mud, measuring spoons,
beakers, warm water
In a beaker measure 100 ml of water. Then stir in1 ml of one item, first in cold water
than warm. Record what happens in the data chart below. Then dispose of the materials
as instructed by your teacher.
COLD
WARM
salt
sand
sugar
baking soda
epsom salt
mud
CONCLUSION: What substances dissolved the fastest (cold or warm water)?
Can you figure out why the ocean is salty and not sweet?
22 FIFTH GRADE – LESSON 6
FILTERING OF WATER
OBJECTIVES:


Analyzing why water cycle is a natural filtration.
Experimenting with filtration.
5
VOCABULARY:





condensation
evaporation
filtration
precipitation
water cycle
MATERIALS:







Giving Water a Second Chance by J. R.Blueford
Funnels
Beakers
Erlenmeyer flask
Sand
Water with soil mix
Coffee filters
BACKGROUND:
Water is our most common natural resource. It is essential to the biology and chemistry
of all living things, it plays a major role in shaping the earth and is an active agent in
many physical reactions. It is important to most life to keep it clean.
There is plenty of water on Earth, but 97% of this water is saline (contains dissolved
salts). Only 3% is fresh and about two thirds of that amount is locked up in polar ice
caps and glaciers; about one third can be found as ground water, lakes, and in the
atmosphere.
Water exists in three states of matter: solid (ice), liquid (water), and gas (vapor) at
normal conditions. Water is a colorless, odorless, tasteless liquid with a melting point of
0° centigrade and a boiling point of 100° centigrade.
Water can be easily cleaned through the water cycle. When water evaporates in the
gaseous phase, it leaves all the impurities behind. Water can also be cleaned through
other natural ways. Humans have created ways in which they can also clean water
without going through a natural water cycle.
23 PROCEDURE:
1. Discu
uss with stu
udents the following
f
ma
ajor points about wate
er or the
hydro
ologic cycle. Draw the
e diagram o
of the waterr cycle.
A.. Water pre
ecipitates frrom clouds as rain, sn
now, sleet, o
or hail to the
Earth’s su
urface.
B.. Dependin
ng on a num
mber of facttors such as soil type, slope,
moisture conditions, and intenssity of precipitation willl either infilttrate
into the ground or ru
unoff into rivvers and streams
C. Virtually no
n water inffiltrates thro
ough paved
d roads and
d parking lo
ots,
so almostt all of it becomes urb
ban runoff. Runoff fro
om rivers, a
and
streams is stored in large bodie
es of water such as lakkes, estuarries,
and oceans.
r
to the atmosp
phere evap
poration from
m the surfa
ace
D. Water is returned
of land orr water bodies, or thro ugh plants by a process called
transpirattion.
E.. Clouds arre formed by
b condens ation of wa
ater vapor th
hat evapora
ated
from the land
l
or oce
eans.
2. Hope
efully this diagram should be famiiliar to stude
ents and th
hey should be
able to
t tell you about
a
each of the com ponents. A
Ask them w
which are
huma
an-made po
ortions of th
he water cyccle? (Reservoir, damss and
canalls.) Where does a sprring get its w
water supp
ply? (Usually from the
groun
nd water pe
ercolating up.) Where does water from the m
mountains w
wind
up? (The
(
ocean
ns.) Which is the newe
est water? (Rain) Olde
est? (Oceans.)
3. Read
d “Give Watter a Secon
nd Chance” so studen
nts can see how the wa
ater
cycle has been cleaning
c
wa
ater for eon
ns of time, b
but now peo
ople can cle
ean
24 it also
o with differrent method
ds.
4. Give students a beak with about
a
150 m
ml of waterr, mix in abo
out 5 ml of “dirt”
water.
from the school ground. Make dirty w
5. Use funnels
f
and
d put in a co
offee filter (sshow them
m how to
put it in by gettin
ng a round filter
f
and fo
old it inhalf a
and then
in hallf again.
6. First have
h
the sttudent just pour
p
water with the filtter and
see how
h
much is
s “cleaned”
7. Repe
eat the expe
eriment but use about 1/3 of the ffunnel
filled with small grained
g
san
nd and makke another dirty
mixtu
ure.
uss with children which
h one clean
ned the mosst and
8. Discu
why.
25