Do Now• Sit SILENTLY and answer the following in your notes.
You do not have to copy the questions, though I am confident some of you will still ask…le sigh
• What are the 2 atoms that make up a water molecule?• Balance the following…
– ___H2 + ____O2 ____H2O
• If water changes from a solid to a liquid to a gas then it is undergoing what kind of change? How do you know?
• What are some ways that we as humans pollute water systems?
What makes water so What makes water so special?special?
WaterWater
•A water molecule (H2O), is made up of threethree atoms --- one oxygen and two hydrogen.
H
HO
Special Properties
• Water is the only substance on Earth that occurs naturally as a solid, a liquid, and a gas.
• It is often referred to as ‘the universal solvent’ because so many other substances dissolve in it.
• This characteristic is one reason that the water encountered on Earth is rarely pure.
So…what makes water so So…what makes water so special?special?
Water is Polar!!!!Water is Polar!!!!
• The oxygenoxygen end “acts” negativenegative• The hydrogenhydrogen end “acts” positivepositive• Causes the water to be POLAR, POLAR,
like a magnet.like a magnet.
Hydrogen Bonds Exist Hydrogen Bonds Exist Between Water MoleculesBetween Water Molecules• Formed between a Formed between a
highly highly Electronegative atom Electronegative atom (like oxygen in (like oxygen in another water) of a another water) of a polar molecule and a polar molecule and a hydrogenhydrogen
• Weak bond, but Weak bond, but strong in great strong in great numbersnumbers
Interaction Between Interaction Between Water MoleculesWater Molecules
Negative Oxygen Negative Oxygen end of one water molecule is end of one water molecule is attracted to the attracted to the Positive Hydrogen Positive Hydrogen end of end of
another water molecule to form a another water molecule to form a HYDROGEN HYDROGEN BONDBOND
What are What are the the
PropertieProperties of s of
Water?Water?
Properties of WaterProperties of Water
•CohesionCohesion
Properties of WaterProperties of Water
•CohesionCohesion•AdhesionAdhesion
Properties of WaterProperties of Water
•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat
Properties of WaterProperties of Water
•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat•High Heat of High Heat of VaporizationVaporization
Properties of WaterProperties of Water
•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat•High Heat of High Heat of VaporizationVaporization
•Less Dense as a SolidLess Dense as a Solid
CohesionCohesion• Attraction between particles of Attraction between particles of
the same substance the same substance (( why water why water is attracted to itself)is attracted to itself)
• Results in Results in surface tensionsurface tension (a (a measure of the strength of watermeasure of the strength of water’’s surface)s surface)
Cohesion …Cohesion …
Helps insects walk across water, but how is it helpful to people?
AdhesionAdhesion• Attraction between two different Attraction between two different
substancessubstances..• Water will make Water will make hydrogen bonds with hydrogen bonds with
other surfacesother surfaces such as glass, soil, such as glass, soil, plant tissues, and cotton. plant tissues, and cotton.
• CapillaryCapillary actionaction-water molecules will -water molecules will ““towtow”” each other along when in a thin each other along when in a thin glass tube.glass tube.
Adhesion Causes Adhesion Causes Capillary ActionCapillary Action
Which gives water the ability to “climb”
structures
High Specific HeatHigh Specific Heat• Amount of heatAmount of heat needed to raise or needed to raise or
lower lower 1g1g of a substance of a substance 1° C1° C..
• Water Water resistsresists temperature changetemperature change, , both for heating and cooling.both for heating and cooling.
– Would you rather walk on sand or in Would you rather walk on sand or in water on a beach on a hot summer day?water on a beach on a hot summer day?
– Which would be warmer that night? Which would be warmer that night? Why?Why?
High Heat of High Heat of VaporizationVaporization
• Water vapor Water vapor forms a kind of global ‘‘blanket” which helps to keep the Earth warm.
• Heat radiated from the sun Heat radiated from the sun warmed surface of the earth is
absorbed and held absorbed and held
by the vaporby the vapor.
Water is Less Dense as Water is Less Dense as a Solida Solid
•Which is ice and which is Which is ice and which is
water?water?
Exit Ticket1.Draw a water molecule with labeled atoms and charges.
2.What is the property called that describes water sticking to itself?
3.Is ice les dense or more dense than liquid water? How do you know?
Do Now
• Why is water’s property of high heat of vaporization important to the earth and more specifically to us?
• What 2 properties of water are important for plants specifically and why?
• Explain why solid water (ice) is able to float on liquid water.
Water Distribution
• Water covers approximately 71% of the Earth’s surface (USGS). Most of this water (97%) is not drinkable because it is saltwater.
Water Distribution
• The majority of freshwater (3%) exists in ice caps, glaciers, and oceans.
• 77% of the freshwater is frozen. Of the 23% that is not frozen, approximately a half of a percent is available to supply living organisms with what they need to survive.
• The availability of water varies with local geography and allows humans to utilize water as a resource.
Salinity
• Salinity = total amount of solid material dissolved in water
• Can be determined by measuring water conductivity
• Typically expressed in parts per thousand (‰)
Figure 5-15
So why is the Ocean so Salty?!
• Dissolved chemicals eroded from the Earth's crust and washed into the sea.
• Solid and gaseous ejections from volcanoes, suspended particles swept to the ocean from the land by onshore winds, and materials dissolved from sediments deposited on the ocean floor have also contributed.
Salinity Cont.• Salinity in ocean waters is increased by
evaporation or by freezing of sea ice and it is decreased as a result of rainfall, runoff, or the melting of ice. The average salinity of seawater is 35 parts per thousand(3.5%). Salinities are much less than average in coastal waters, in the polar seas, and near the mouths of large rivers.
• In recent years, salinity has been changing across the world’s oceans. Why do you think that is?
Processes affecting seawater salinity
• Processes that decrease seawater salinity:– Precipitation– Runoff– Icebergs melting– Sea ice melting
• Processes that increase seawater salinity:– Sea ice forming– Evaporation– Hydrothermal vents
What are Hydrothermal Vents?
Hydrothermal Vent• Hydrothermal vent- a deep-sea hot spring
where heated seawater forces its way up through the crust.
• Discovered rich communities in 1977.• Temperatures range from 10-20⁰C (50-68⁰F)
to 350⁰C (660⁰F).• Mineral particles such as sulfides and
carbonates precipitate to form chimneys.
Mid-Ocean Ridge
Hydrothermal Vents
Where are vents located?
Where magma is close to the surface – Mid Ocean Ridges.
Mid-Ocean Ridges
http://www.divediscover.whoi.edu/ridge/axial.html
19771st vent found by Alvin
Alvin?
Alvinhttp://www.youtube.com/watch?v=XotF9fzo4Vo
Submersibles, ROVs, & AUVs
http://www.divediscover.whoi.edu/vents/vent-infomod.html
STEP 1
•Cold water (2oC) seeps through cracks and is heated up (up to 400oC)
How are vents created?
STEP 2
•Water heated to 350-400oC – high temps. facilitate leaching of minerals from rock.
•Oxygen is removed chemically
•Picks up dissolved metals (Fe, Cu, Zn).
•H20 picks up Hydrogen sulfide.
STEP 3
•Hot liquid under pressure finds an exit.
•Dissolved metals and H2S are carried up and out.
•Effluent is acidic and toxic to most animals.
White and Black Smokers
Black SmokerHottest of all vents
monosulfide. This compound gives the smoker its black color.They spew mostly iron and sulfide, which combine to form iron monosulfide. This compound gives the smoker its black color.
WHITE SMOKERS
•White smoke contains silica
•Anhydrite is created (white mineral)
•Contains compounds of barium, calcium, and silicon
Still hot enough to cook pasta – but not as hot as black smokers
Vent crabs
Zooarcid Fish (Eelpout)
Giant Vent Mussel
Lepetodrilus- limpets
Pompeii Worm
Giant Hydrothermal Vent Clam
Anemones
Constituents of ocean salinity
• Average seawater salinity = 35‰ (3.5%)
• Main constituents of ocean salinity:– Chloride (Cl–)– Sodium (Na+)– Sulfate (SO4
2–)– Magnesium (Mg2+)
Figure 5-13
Salinity variations
Location/type Salinity
Normal open ocean 33-38‰
Baltic Sea 10‰ (brackish)
Red Sea 42‰ (hypersaline)
Great Salt Lake 280‰
Dead Sea 330‰
Tap water 0.8‰ or less
Premium bottled water 0.3‰
Seawater desalination
• Desalination methods:– Distillation
• Solar
• Heat
– Electrolysis– Reverse osmosis– Freeze separation
Figure 5-25
Distillation
Reverse Osmosis
Figure 5-26
But why do we really care about salinity anyway?
• The ocean currents are affected by salinity and ocean currents regulate climate around the world.
• The earths oceans and seas are also the biggest recyclers of gasses in the atmosphere.
• Finally the oceans store heat that allows us to have the seasons.
What are Currents?
• Currents are the slow movement of sea water by different factors– Surface currents are caused by wind and
temperature variations – Deeper currents are caused by changes in
density (salinity) and temperature– http://www.youtube.com/watch?
v=qeZgJzt3m04
Heat Transport by Currents
• Surface currents play significant roles in transport heat energy from equatorial waters towards the poles
• May serve as “heat sources” to cooler overlying air, “heat sinks” from warmer
• Evaporation and condensation participate in latent heat exchanges
Matter Transport and Surface Currents
• Currents also involved with gas exchanges, especially O2 and CO2
• Nutrient exchanges important within surface waters (including outflow from continents) and deeper waters (upwelling and downwelling)
• Pollution dispersal• Impact on fisheries and other resources
The currents move in a circular motion
Deep current and Surface current interaction
What happens to the regular cycle when salinity is disrupted?
• The normal circular motion gets bent and skewed a bit.
Gyres are large circular-moving loops of waterFive main gyres (one in each ocean
basin):• North Pacific• South Pacific• North Atlantic• South Atlantic• Indian
• Generally 4 currents in each gyre• Centered about 30o north or south
latitude
Current GyresCurrent Gyres
• “Great Pacific Garbage Patch”
• Estimate: 46,000 pieces of floating garbage/mi2.
North Pacific Subtropical Gyre
North Pacific Subtropical Gyre
135° to 155°W and 35° to 42°N
North Pacific Subtropical Gyre
http://marinedebris.noaa.gov/info/patch.html#6
Great Pacific Garbage Patch- Good Morning America 2010http://www.youtube.com/watch?v=Co43TXJXryI
What do Nike shoes, What do Nike shoes, rubber ducks, and hockey rubber ducks, and hockey gloves have to do with gloves have to do with currents?currents?
Lost at Sea
•January 1992 - shipwrecked in the Pacific Ocean, off the coast of China
•November 1992 - half had drifted north to the Bering Sea and Alaska; the other half went south to Indonesia and Australia
•1995 to 2000 - spent five years in the Arctic ice floes, slowly working their way through the glaciers2001 - the duckies bobbed over the place where the Titanic had sunk
•2003 - they were predicted to begin washing up onshore in New England, but only one was spotted in Maine
•2007 - a couple duckies and frogs were found on the beaches of Scotland and southwest England.
Duckie Progress
The Water Cycle
By Mr. Miller
Water never leaves the Earth. It is constantly being cycled through the atmosphere, ocean, and land. This process, known as the water cycle, is driven by energy from the sun. The water cycle is crucial to the existence of life on our planet.
The Water Cycle
During part of the water cycle, the sun heats up liquid water and changes it to a gas by the process
of evaporation. Water that evaporates from Earth’s oceans, lakes, rivers, and moist soil rises
up into the atmosphere.
The process of evaporation from plants is called The process of evaporation from plants is called transpirationtranspiration. (In other words, it. (In other words, it’’s like plants s like plants sweating.)sweating.)
As water (in the form of gas) rises higher in the atmosphere, it starts to cool and become a liquid again.
This process is called condensation. When a large amount of water vapor condenses, it results in the
formation of clouds.
When the water in the clouds gets too heavy, the water falls back to the earth. This is called
precipitation.
When rain falls on the land, some of the water is absorbed into the ground forming pockets of water called groundwater. Most groundwater eventually
returns to the ocean. Other precipitation runs directly into streams or rivers. Water that collects in rivers,
streams, and oceans is called runoff.
Stormwater Runoff and Water Quality
Stormwater Runoff
Definition:
Rainfall that, instead of soaking into the ground, flows into water bodies picking up pollutants along the way
http://www.kytc.state.ky.us/EnvAnalysis/Stormwaterquality/Gen_info_edu.htm
River Basin
Definition: defined area where all water within the area flows into a common water body
There are 17 different river basins in NCYou live in the Catawba River Basin, which
has the largest number of people so what implications do you think there are for the environment here?
NC River Basins
http://www.cgia.state.nc.us/Portals/0/images/examples/nc_rivbasins.jpg
Pollution
As stormwater flows across streets and lawns, it picks up chemical pollutants
All pollution in a river basin accumulates in the common water body
Types of Pollution
Point Source Pollution
Definition-localized source of pollution, usually industrial and coming from a pipe Examples
Industry
Nonpoint Source Pollution
Definition- general and indirect water pollution from many diffuse sources
Examples Agricultural Runoff Animal Waste Residential Property Runoff Parking Lot and Road
Runoff
http://www.liverpool.nsw.gov.au/LCC/INTERNET/me.get?site.sectionshow&PAGE1230&BODY
What’s wrong with this picture?
http://www.ncstormwater.org/pages/workbook_pollution_solutions.html
Visual Indicators of Water Quality
Diverse OrganismsBugs as Indicators of Water Quality
Mayflies and Caddisflies cannot tolerate water pollution, therefore their presence in a water body indicates good water quality.
Mayfly larvaehttp://swittersb.files.wordpress.com/2008/08/mayfly20nymph.jpg
Caddisfly larvaehttp://www-staff.lboro.ac.uk/~gymfj2/Caddisfly.htm
Measuring Water Quality
Dissolved OxygenWater TemperaturepHExtremely high or low
levels of any of these indicate poor water quality
A YSI Meter is used to measure these quantities.
How do we cleanse our waters?!
Riparian buffersWetlandsStormwater Best Management Practices
Raingardens, Cisterns, Rain Barrels, Permeable Pavement