The Amazing Water Molecule. States of Water Water is unique in that it is the only natural state that is found in all three states. Water is unique in.

The Amazing Water The Amazing Water MoleculeMolecule

States of WaterStates of Water Water is unique in that it is the only Water is unique in that it is the only

natural state that is found in all three natural state that is found in all three states.states.

LiquidLiquid

SolidSolid

Gas (steam)Gas (steam)

Water StructureWater Structure A water molecule is A water molecule is

neutralneutral However the oxygen However the oxygen

atom it has a stronger atom it has a stronger attraction for electrons attraction for electrons than the hydrogen than the hydrogen atom with a single atom with a single proton in its nucleus.proton in its nucleus.

Polarity Polarity – due to an – due to an uneven distribution of uneven distribution of electrons between the electrons between the oxygen and hydrogen oxygen and hydrogen atomsatoms

More StructureMore Structure Since opposites Since opposites

electrical charges electrical charges attract, water attract, water molecules tend to molecules tend to attract each other attract each other making water kind of making water kind of “sticky”“sticky” or cohesion or cohesion

The side with the The side with the hydrogen atoms (+) hydrogen atoms (+) attracts the oxygen attracts the oxygen side (-) of a different side (-) of a different molecule molecule

Universal SolventUniversal Solvent Water is called the Water is called the

“universal solvent”“universal solvent” because it dissolves because it dissolves more substances more substances than any other liquidthan any other liquid

So when ever water So when ever water goes through the goes through the ground or our ground or our bodies, it takes bodies, it takes along valuable along valuable chemicals, minerals, chemicals, minerals, and nutrientsand nutrients

Solutions and SuspensionsSolutions and Suspensions

Mixture Mixture – material – material composed of two or composed of two or more elements or more elements or compounds that compounds that physically mixed physically mixed together but not together but not chemically chemically combinedcombined

Types of mixtures Types of mixtures are are solutionssolutions and and suspensionssuspensions

SolutionsSolutions All components of a solution are evenly All components of a solution are evenly

distributed throughout the mixturedistributed throughout the mixture SoluteSolute – the substance that is dissolved – the substance that is dissolved SolventSolvent –the substance in which a solute –the substance in which a solute

dissolvesdissolves Water is a solventWater is a solvent

SuspensionSuspension SuspensionSuspension – when materials do not – when materials do not

dissolve but separate into pieces so small dissolve but separate into pieces so small that they do not settle out. that they do not settle out.

The movement of water molecules keeps The movement of water molecules keeps the small particles suspendedthe small particles suspended

Acids, Bases and pHAcids, Bases and pH A water molecule can react to form ionsA water molecule can react to form ions

HH22 0 H 0 H++ + 0H + 0H--

WaterWater hydrogen + hydroxide hydrogen + hydroxide

Blue Litmus paper checks for acids

Red Litmus paper checks for bases

Scientists derived a measurement system to Scientists derived a measurement system to indicate the concentration of Hindicate the concentration of H++ ions in solution ions in solution

The pH scale ranges from 0 - 14The pH scale ranges from 0 - 14

AcidAcid

Acidic solutions Acidic solutions contain higher contain higher concentrations of concentrations of H+ ions than pure H+ ions than pure waterwater

pH value 1- 6pH value 1- 6

BasesBases

Basic or alkaline Basic or alkaline solutions contain solutions contain lower lower concentrations of concentrations of H+ ions pure waterH+ ions pure water

Bases have pH Bases have pH values 8 - 14values 8 - 14

Properties of water - Properties of water - FreezingFreezing

Water freezes at 32 degrees FahrenheitWater freezes at 32 degrees Fahrenheit Water boils at 212 degrees FahrenheitWater boils at 212 degrees Fahrenheit Water freezes at 0 degrees CelsiusWater freezes at 0 degrees Celsius Water boils at 100 degrees CelsiusWater boils at 100 degrees Celsius Unique property – water floats in itself!Unique property – water floats in itself!

In its solid form (ice) it is less dense than the In its solid form (ice) it is less dense than the liquid form, which is why it floats liquid form, which is why it floats

Water Properties – Specific Water Properties – Specific HeatHeat

Water has a high specific heatWater has a high specific heat This means water can absorb a lot of This means water can absorb a lot of

heat heat BEFORE BEFORE it gets hotit gets hot It helps regulate the rate at which air It helps regulate the rate at which air

changes temperaturechanges temperature This is why the temperature change This is why the temperature change

between seasons is gradual rather between seasons is gradual rather than sudden – especially the oceansthan sudden – especially the oceans

Water Properties – Surface Water Properties – Surface TensionTension

Water has a very high Water has a very high surface tensionsurface tension

In other words it is stick In other words it is stick and elastic and tends to and elastic and tends to clump together in drops clump together in drops rather than spread out rather than spread out in a thin filmin a thin film

It is this property that is It is this property that is responsible for another responsible for another property – capillary property – capillary actionaction

Water Property – Capillary Water Property – Capillary ActionAction

It occurs because It occurs because water is stickywater is sticky

Water molecules stick Water molecules stick to each other and to to each other and to other substances such other substances such as glass, cloth, organic as glass, cloth, organic tissue, and soiltissue, and soil

Importance: Importance: Allows water and its Allows water and its

dissolved substances dissolved substances through:through:

the roots of plantsthe roots of plants The tiny blood The tiny blood

vessels in our bodyvessels in our body

Water Property: Hardness Water Property: Hardness

Water described as "hard" is high in dissolved minerals, specifically calcium and magnesium. Hard water is not a health risk, but a nuisance because of mineral buildup on fixtures and poor soap and/or detergent performance.

Water is a good solvent and picks up impurities easily. Pure water -- tasteless, colorless, and odorless -- is often called the universal solvent. When water is combined with carbon dioxide to form very weak carbonic acid, an even better solvent results.

As water moves through soil and rock, it dissolves very small amounts of minerals and holds them in solution. Calcium and magnesium dissolved in water are the two most common minerals that make water "hard." The degree of hardness becomes greater as the calcium and magnesium content

Common Water Common Water MeasurementsMeasurements

Water TemperatureWater Temperature Water temperature is not Water temperature is not

only important to only important to swimmers and fisherman, swimmers and fisherman, but also to industries and but also to industries and even fish and algae. A lot of even fish and algae. A lot of water is used for cooling water is used for cooling purposes in power plants purposes in power plants that generate electricity. that generate electricity. They need cool water to They need cool water to start with, and they start with, and they generally release warmer generally release warmer water back to the water back to the environment. environment.

The temperature also can The temperature also can affect the ability of water to affect the ability of water to hold oxygen as well as the hold oxygen as well as the ability of organisms to ability of organisms to resist certain pollutants.resist certain pollutants.

pHpH pH is a measure of pH is a measure of

how acidic/basic how acidic/basic water is. water is.

Pollution can Pollution can change a water’s change a water’s pH, which in turn pH, which in turn can harm animals can harm animals and plants living in and plants living in the water.the water.

TurbidityTurbidity

Measures the amount of particulate Measures the amount of particulate matter that is suspended in water.matter that is suspended in water.

Materials that can cause turbidity areMaterials that can cause turbidity are ClayClay SiltSilt Plankton/microscopic organismsPlankton/microscopic organisms

AmmoniaAmmonia One of the most common aquatic One of the most common aquatic

pollutants is ammonia.pollutants is ammonia. It is discharged from industrial, municipal It is discharged from industrial, municipal

and agricultural wastewater.and agricultural wastewater. Ammonia is a major component of urineAmmonia is a major component of urine Ammonia is extremely toxic to aquatic life Ammonia is extremely toxic to aquatic life

and is an oxygen demanding substance.and is an oxygen demanding substance. Exposure to chronic levels over a long Exposure to chronic levels over a long

period is more susceptible to disease, period is more susceptible to disease, reduced reproduction and growthreduced reproduction and growth

Nitrite/NitrateNitrite/Nitrate

Ammonia, nitrite and nitrate are Ammonia, nitrite and nitrate are related by the process of nitrification, related by the process of nitrification, which is the oxidation of ammonia which is the oxidation of ammonia and nitrateand nitrate

In the presence of oxygen, ammonia In the presence of oxygen, ammonia is oxidized by Nitrosomonas bacteria is oxidized by Nitrosomonas bacteria to nitriteto nitrite

Nitrite is then oxidized by Nitrobacter Nitrite is then oxidized by Nitrobacter bacteria to form nitratebacteria to form nitrate

Nitrite/NitrateNitrite/Nitrate

Nitrite, like ammonia is extremely toxic Nitrite, like ammonia is extremely toxic to plant life, but is not considered an to plant life, but is not considered an environmental problem because it environmental problem because it occurs in relatively low concentrations.occurs in relatively low concentrations.

Nitrate is relatively nontoxic to aquatic Nitrate is relatively nontoxic to aquatic organisms and is not considered an organisms and is not considered an environmental problemenvironmental problem

ChlorineChlorine

Chlorine is a chronic source of stress Chlorine is a chronic source of stress on the aquatic environment. on the aquatic environment.

Free and combined chlorine are Free and combined chlorine are extremely toxic to fish. Any chlorine extremely toxic to fish. Any chlorine is not considered safe for fish.is not considered safe for fish.

The main source of chlorine in fresh The main source of chlorine in fresh water is domestic wastewater and water is domestic wastewater and industryindustry

Dissolved OxygenDissolved Oxygen

Dissolved oxygen is need by fish and Dissolved oxygen is need by fish and zooplankton to survive.zooplankton to survive.

Rapidly moving water contains large Rapidly moving water contains large amounts of dissolved oxygen.amounts of dissolved oxygen.

Stagnant water contains little Stagnant water contains little dissolved oxygen.dissolved oxygen.

Dissolved Oxygen and Algae Dissolved Oxygen and Algae BloomsBlooms

Oxygen depletion due to algae Oxygen depletion due to algae blooms is a common problem in blooms is a common problem in aquatic environments.aquatic environments.

When the algae die, bacteria start to When the algae die, bacteria start to decompose them and in the process decompose them and in the process use up the oxygen.use up the oxygen.