chapter 3. warm up 9/12 ridges and trenches!! 1. in a complete sentence, compare and contrast ridges...
TRANSCRIPT
Chapter 3
Warm up 9/12
Ridges and Trenches!!1. In a complete sentence, compare and contrast ridges and trenches by the plate boundary at which they occur2. Name the 2 major ridges of the Pacific and Atlantic Oceans3. At which geologic feature is seafloor created?4. At which trench is seafloor destroyed?
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Warm Up 2/11In a complete
sentence, describe the differences between passive and active margins.
Would point A fall on a passive margin? Why or why not?
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Agenda 2/11 – 4th BlockStart talking about Ch.3 ~ 10 minutesIn lab groups, begin lab questions & design
model ~ 40 minutes
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9:15-10:09-4th Block10:09-10:15-Change10:15-12:15-3rd Block/Lunch (30 min. per lunch)12:15-Dismiss from 3rd Block (Students will return from 4th lunch to 3rd block at 12:10).
Salinity and Density LabWhat is meant by “mass”?
The weight in grams of your solutionWhat is meant by “volume”?
The amount of space your solution occupies, measured here in millileters
Salinity and Density LabWill be working in assigned groupsEach group will assign a leader responsible
for directing members and a recorder for writing data table
Salinity and Density LabEach group needs:
five beakers (between 250ml and 400ml) labeled A-E with tape
One 150ml beaker for water measurementOne 25ml graduated cylinderSaltScaleScoop/spoonLab sheet [DO NOT WRITE ON]CalculatorSeparate paper for recording data, conclusion
answers
Lab 9/18 Salinity and DensityEach group will need to construct their own
data table to submit. Each group will need to:
answer Conclusion questions 1 & 2, and 4create a graph of their data.
Homework – due Fridayhttp://science.nasa.gov/earth-science/oceanography/physical-ocean/salinity/
1.How does salinity affect movement of ocean currents?
2.Is it true that the ocean stores more heat in its upper meter than the entire atmosphere stores? Why or why not?
3.How can ocean salinity be measured?4.What factors can affect salinity readings?5.Where is the saltiest area in the open ocean? Why
is it so salty?
Warm Up 2/181. Place the layers of the earth in order from
inside outside2. Identify the layer of the earth that contains
convection currents.3. Identify the layer of the earth that contains
tectonic plates. 4. What is one important toxic substance
released from hydrothermal vents?
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Agenda 2/18Continue Ch.3 … density/salinity lab
tomorrowReview for Ch.2 … Exam tomorrow!
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Bill Nye Water
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Water- a unique compoundWater is a polar molecule (slightly
charged)molecules are attracted to one another –
hydrogen bonds.only substance to exist naturally in all 3 states
of matter!
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Oppositely charged ends attracted each other like poles on a magnetic
POLAR MOLECULE
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Three State of WaterSolid (ice)Liquid (water)Gas (vapor)
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Three States of WaterHeating Water
H2O molecules in constant motion
Adding enough energy = the hydrogen bonds break & H2O boils
Evaporation : molecules breaking hydrogen bonds and escaping liquid phase
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TEMPERATURE = MOLECULAR MOVEMENT
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Three States of WaterCooling Water
Decrease in temperature = decrease in molecular speed
In cooler temps, molecules move slower and pack close together
Volume decreases without changing the mass = denser
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D = Mass Volume
TEMPERATURE = MOLECULAR MOVEMENT
Three States of WaterDecreasing temperatures increases density
Why coldest water in the ocean sinks
However, when water gets cold enough to form ice, hydrogen bonds separating molecules lengthen, increasing volume.
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D = Mass Volume
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Density =
0.5 0.25
Density =
>
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ICE WITH LONGER HYDROGEN BONDS
Ice formation
Three States of WaterCooling Water
H2O cools so much that hydrogen bonds overcome molecular movement, fixing molecules in 3D pattern
Crystals: solids that consist of 3D fixed patterns
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Three states of WaterWater is less dense as a solid than as a liquid
Floating ice insulates water and keeps it warm enough to support life!
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This is why ice floats!!!!!!!!!
Water: Latent HeatLatent heat of melting: the amount of energy
needed to melt iceIce requires a lot of heat to melt because of
hydrogen bondsReverse is true: a lot of heat must be removed
from liquid H2O to freeze it
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This is why it takes a long cold spell to freeze a large body of water
Bill Nye
Water: Latent Heat
Heat capacity : a substances ability to store energy
AKA “specific heat” : the amount of heat required to raise a ‘unit mass’ of a substance by 1° temperature
H2O has a very high heat capacity!!!!Means it can absorb heat without large jumps
in temperatureProvides stable environment for marine
organisms
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Ocean can absorb 1000 times the heat energy as the atmosphere without changing temperature, and even IT’S heating up!
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Ocean Warming
Water: “The Universal Solvent”Water can dissolve
more substances than any other natural compoundEspecially salts!Due to polarity, or
charge, of molecules
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Solubility
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Water Relationships #11. Density & Salinity
Increasing salinity increases densityWhy?
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Increasing the amount of dissolved material increases mass, but volume stays same
Pure water has a density of 1.0 g/ml. Average density of ocean water at the surface is 1.025 g/ml.
Water Relationships #22. Density and Temperature: INDIRECTLY
PROPORTIONALTemperature greatly affects the density of water.Review:
Decrease in temperature = decrease in molecular speed
Cooling down causes molecules to pack closer together, reducing volume, and thus, increasing density
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TEMPERATURE = MOLECULAR MOVEMENT
TEMPERATURE = MOLECULAR MOVEMENT
Proportional relationship true until water becomes ice
Water Relationships #33. Density and Buoyancy
Buoyancy: upward force exerted by a fluid that opposes the weight of an immersed object
The more dense the liquid, the more force it exerts upward
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Example: The Dead Sea or Great Salt LakeDead Sea Float
Buoyancy of Water Demonstration
Set up the following observation table in your notes:
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Salt Content
Observation
0 small cups
1 smallcup
2 small cups
3 small cups
Predictions for how the egg will float?
Water RelationshipsReview: temperature affects density of waterReview: salinity affects density of waterTHEREFORE… salinity and temperature
affect ocean water. Temperature in open ocean varies between 28°
to 86°F
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WAIT … At what temperature does pure water freeze?
How can ocean water be 28° and still liquid??
Salt lowers the freezing point of water!!!!
Warm Up 9/20The winter of 1984-85 was particularly cold
in Europe. The northern part of the Black Sea froze, which is rare. The Adriatic Sea, located to the east, had just as cold a winter but never froze. The Black Sea has an unusually low salinity at 18%. What would you guess about the salinity of the Adriatic?
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GROUP PENNIES (PURE) PENNIES (SALT)
Buoyancy Lab Questions – Write Question first. Use complete sentences.1. Which type of water exerted a greater buoyant force on
your boat? Why?
2. How would increasing the salinity of the water affect the buoyancy of your boat?
3. In which type of water would your boat be more buoyant: cold saltwater or warm saltwater? Why?
4. What is the relationship between temperature and density?
5. Describe the role molecular movement plays in the relationship between density and temperature.
6. What is the relationship between density and buoyancy?
7. What changes would you make to your boat or water to increase its buoyancy?
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SeawaterSolids dissolved in
seawater present due Weathering of rocks on earthRelease of minerals
from interior earth at hydrothermal vents
Na+ and Cl- make up 85% of dissolved solids
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SeawaterSalinity: total amount of salt dissolved in
seawater # of grams NaCl/1,000 grams H2Oexpressed in PSU (practical salinity units)
same as ‰ (parts per thousand … 1/1000)
Example: If we evaporated 1,000 grams of seawater and were left with 35 grams of salt, our seawater’s salinity in PSU or parts per thousand would be ______________.
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35 ‰
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Salinity Rule of constant proportions: the proportions
of salts in the ocean remains constant.Chemistry of ocean is well-mixed and
relatively constant.Ions added and removed continuously and
simultaneously
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HOW?
Precipitation, evaporation, runoff!!!
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Dissolved GasesThree most important:
1. Oxygen2. Carbon Dioxide (80%)3. Nitrogen
Gases dissolve more easily in colder water!Gas exchange between the ocean and the
atmosphere occurs at the surface
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Dissolved GasesO2 concentration in water strongly affected
by organisms presentPhotosynthesisRespiration
Low dissolved O2 levels leave ocean susceptible to depletion
Oxygen minimum layer: 1600 ft. deep layer of ocean where levels are virtually zero.
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But life still survives!!!!!!!!!!
Biogeochemical CyclingPhotosynthesis,
Respiration, and Nitrogen cycles provide important substances for life to thrive
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The Three layered OceanCold, salty water sinks- the ocean is
stratified.Warmer water stays near the surfaceThe layer of rapid temperature change in
between is called a thermocline.
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Warm Up 9/23In a complete sentence, describe how an
organism might adapt for conditions below the oxygen minimum layer?
How deep will you find the oxygen minimum layer?
In a complete sentence, describe one way dissolved solids enter the ocean.
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Water ClarityDifferent colors of light penetrate the ocean
at varying depthsWater needs to be transparent so sunlight
can penetrate
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Why do we need sunlight to penetrate?
Photosynthesis
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Red is absorbed quickly
Blue can travel to the greatest depths
PressureOn land, we live in 1 atm, or 14.7 psiIn the ocean, organisms experience this PLUS the weight
of the water.Pressure increases 1 atm with every 10
meters in depth. (an extra 14.7psi with every 33 ft)
Gases expand and contract with pressure changes
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Notice red balloon compressing at different pressures
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Swim bladder pushed stomach out of his mouth due to pressure!!
Pressure videosGory Diver Video
James Cameron
Free dive
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Pressure Math
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Thermohaline circulationDeep water circulation that is driven by
density of a water massGenerated when there are very cold surface
temperaturesCold water mass sinks, generating the
current
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Motion in the Oceanat surface in form of surface currents and
waves
Coriolis EffectRotation of earth causes bending over its
surfaceNorthern Hemisphere: deflects to rightSouthern Hemisphere: deflects to left
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What drives this oceanic movement? Wind!
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Wind Patternsmovement driven by heat from sun
Hot air from equator risesNearby air rushes in to replace it = trade
windsExamples of other wind zones:
1. Polar easterlies2. westerlies
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Would hot air sink or rise? Is hot air denser than cold air?
Help drive ocean movement
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Warm Up 9/24Calculate the density of a 10.35 gram
saltwater solution in a 10 ml cylinder.
If pressure increases 14.7 psi (1 atm) every 33ft, how many atm of pressure would you feel if you dove 168 feet below the surface?
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Wind PatternsWhy is wind important for ocean movement?
Pushes sea surface and creates currents!
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Bill Nye science clip
Ekman spiralsCoriolis effect
causes surface current to occur at a 45 degree angle from the wind
Ekman spiral = each layer down the water column is pushed by the one above it and pushes the one below it
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Wiki Webquest!Partner upGet an ipad“google” David W. Butler High SchoolClick “Faculty and Staff” linkFind and click the globe next to my name1. “Motion of Ocean webquest2. “Ocean currents and pollution”
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Warm Up 9/25Your solution of saltwater has a density of
1.025 gram/ml. It is in a volume of 10 ml. What is the mass of your solution?
If you increase salinity of water, what effect will that have on …freezing pointDensitybuoyancy
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Label the gyres!
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Currents to Know!Gulf Stream
Carries warm water up eastern coast of USResponsible for mild temperatures of North
Carolina also brings hurricanes!
California CurrentCold watersHeavy fogExample of upwelling current: transports
phosphates and nitrates to water surface
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More nutrients = more organisms present
CurrentsTurbidity
Carry sedimentGravity pushes them
down the continental slope
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CurrentsCounter Current = Slow-moving deep currentRip Current
fast-moving current (up to 2 meters per second!!)
Flows seaward from the beachnarrow pathway for water from beach to return
to sea
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http://www.youtube.com/watch?v=-hCZuYzNujI
NOAA about 100 people on average die each year in a rip tide
Ocean in MotionREVIEW: water has a high heat capacity
This means it transports heat well!!!Warm currents on western side of gyres
carry solar heat from equatorCold currents on eastern sides of gyres
carry cold water from polar
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What does high heat capacity mean? Stores energy/absorbs heat without large jumps in temperature
Ocean in MotionOcean currents act like a giant thermostat
Warm polesCool tropics
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El Nino was the result of fluctuations in current patterns!
http://www.youtube.com/watch?v=7FVZrw7bk1w
Warm Up 9/26The current responsible for cool water
temperatures and fog in San Francisco is the Humboldt Current.
The Gulf Stream is a cold current responsible for freezing temperatures in North Carolina.
Turbidity currents flow seaward from the beach, move quickly, and are responsible for 100 deaths each year at US beaches.
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Rewrite the entire sentence so that it is correct.
Agenda15 minutes to finish bottleGPGP – create posters & presentNotes on wavesStudy guides [if time]
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Marine Debris videosGPGP plastics
GPGP oprah
Atlantic GP
Tsunami Debris
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Warm Up 9/27What property of water allows it to be the
“universal solvent”?Why do dense liquids like saltwater have a
higher buoyancy than less dense fluids like freshwater?
If we evaporated 1,000 grams of seawater and were left with 31 grams of salt, what would our seawater’s salinity be in PSU or parts per mil?
AgendaPresentationsNotesWorksheets
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Warm up 9/30For the diagram at
right,identify the wave
partsindicated at numbers
1-4.
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AgendaAbsent presentationsNotesIndependent questions - tidesPartner – chart the tides
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Review session still Tuesday 10/1
Test Thursday?
WavesWind drives surface
currents and creates waves
Anatomy of a waveCrest – highest partTrough – lowest
partHeight- vertical
distance from crest to trough
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Height
power station
WavesAnatomy of a wave
Wavelength- distance from crest to crest
Period- time for a wave to go by a given point
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Period
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Wave FormationBegin to form as soon as wind starts to blowWave size
as wind blows faster and for a longer time
Depend on fetch (span of open ocean over which wind blows)
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Where in this bay is the fetch largest?
Life cycle of a waveSeas = wind blows to push wave crests up to
sharp peaksSwells = waves blow away from wind and settleSurf = waves fall and break
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Wave diagrams
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Wave diagrams
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Wave simulatorhttp://education.nationalgeographic.com/
education/multimedia/interactive/wave-simulator/?ar_a=1
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Warm Up 10/1If you owned a seaside home and a bad storm brought heavy winds and high surf to your coastline, would you prefer it to be during a new moon or a quarter moon? Why?
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Agenda20 minutes to work on tidal curvesCh. 4 notesStudy guides with partners on ipads
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Tidal Curve ExtensionsWhat days of the month do you see a quarter
moon? Full moon? New Moon?Calculate the tidal ranges on these days.Do these tidal ranges confirm your
estimates?What causes tidal bulges on New Moon and
Full Moon days?
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TidesRhythmic rise and fall of sea surfaceDominant influence on near-shore sea life
Expose and submerge organismsDrive circulation of baysTrigger spawning [grunion] grunion run
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Life in the tide pool includes environmental fluctuations, benefits, risks…
tide pool creatures
Tides - CauseCaused by the
gravitational attraction of the moon AND the sun on Earth’s ocean, combined with earth’s rotationCentrifugal force of
rotation and gravitational attraction balance unevenly
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Tides - CauseSide of earth near moon moon’s gravity is
stronger and pull water towards moon
Side of earth further from moon centrifugal force is stronger and pushes water from moon
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These bulges in water due to unbalanced forces causes high tides and low tides!!
Moon and Tides
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Video
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The moon causes high tides and low tides because of water bulges!!!
Tides - CauseHigh tides and low tides
Typically, 2 high tides and 2 low tides/day = Semidiurnal
Full tidal cycle = 24 hours, 50 minutes
The sun affects tides as well!
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How many tides occur per day?
Tides - CauseGravitation pull of sun also affects
tidesSun is larger than moon but MUCH
farther awayThe sun’s effect on tides is about half as
strong as moonTidal range- difference in water level
between low and high tides
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Tides - CauseSpring tides- occur during new and full
moons when sun, moon and earth are in a line = Large tidal range
Neap tides- occur during first and third quarter = Smaller tidal range- tides not as ‘extreme’
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Bill Nye Moon
0- 4:10 phases
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Time lapsed video
History Channel Moon Phases
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Exit QuestionsUnder what conditions might salinity change
in the ocean?
Describe the motion of the water particles in waves
How does the position of the sun affect tidal range?
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Warm Up 9/18Write the following sentences. Circle the mistakes
and then rewrite the sentence so it is correct.
Polarity, or charge difference, on water molecules is due to a very positive oxygen molecule and two very negative hydrogen molecules.
When enough energy is added to water, bonds are formed and it condenses.
Water is held to other water molecules with ionic bonds.
Lab 9/18 Salinity and DensityThe purpose of this lab to answer the
following questions:How does salinity affect water density?How does salinity affect water movement?
To answer these questions, you will be calculating the density of saltwater solutions of various concentrations
Lab 9/18 Salinity and Density
Warm Up 9/19In a complete sentence, describe the property
of seawater that contributed to the color banding in lab yesterday.
At what temperatures does water change state?Solid to liquid at _______ °F ( ___________°C)Liquid to gas at ________ °F ( ___________°C)
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Properties of Water
Make-up work!!!!