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 that it is the only natural state that is found in all three states. Liquid Liquid Solid Solid Gas (steam) Gas (steam)

Water Structure A water molecule is neutral A water molecule is neutral However the oxygen atom it has a stronger attraction for electrons than the hydrogen atom with a single proton in its nucleus. However the oxygen atom it has a stronger attraction for electrons than the hydrogen atom with a single proton in its nucleus. Polarity – due to an uneven distribution of electrons between the oxygen and hydrogen atoms Polarity – due to an uneven distribution of electrons between the oxygen and hydrogen atoms

More Structure Since opposites electrical charges attract, water molecules tend to attract each other making water kind of “sticky” or cohesion Since opposites electrical charges attract, water molecules tend to attract each other making water kind of “sticky” or cohesion The side with the hydrogen atoms (+) attracts the oxygen side (-) of a different molecule The side with the hydrogen atoms (+) attracts the oxygen side (-) of a different molecule

Universal Solvent Water is called the “universal solvent” because it dissolves more substances than any other liquid Water is called the “universal solvent” because it dissolves more substances than any other liquid So when ever water goes through the ground or our bodies, it takes along valuable chemicals, minerals, and nutrients So when ever water goes through the ground or our bodies, it takes along valuable chemicals, minerals, and nutrients

Solutions and Suspensions Mixture – material composed of two or more elements or compounds that physically mixed together but not chemically combined Mixture – material composed of two or more elements or compounds that physically mixed together but not chemically combined Types of mixtures are solutions and suspensions Types of mixtures are solutions and suspensions

Solutions All components of a solution are evenly distributed throughout the mixture All components of a solution are evenly distributed throughout the mixture Solute – the substance that is dissolved Solute – the substance that is dissolved Solvent –the substance in which a solute dissolves Solvent –the substance in which a solute dissolves Water is a solvent Water is a solvent

Suspension Suspension – when materials do not dissolve but separate into pieces so small that they do not settle out. Suspension – when materials do not dissolve but separate into pieces so small that they do not settle out. The movement of water molecules keeps the small particles suspended The movement of water molecules keeps the small particles suspended

Acids, Bases and pH A water molecule can react to form ions A water molecule can react to form ions H 2 0 H + + 0H - H 2 0 H + + 0H - Water hydrogen + hydroxide Water hydrogen + hydroxide Blue Litmus paper checks for acids Red Litmus paper checks for bases

Scientists derived a measurement system to indicate the concentration of H + ions in solution Scientists derived a measurement system to indicate the concentration of H + ions in solution The pH scale ranges from The pH scale ranges from

Acid Acidic solutions contain higher concentrations of H+ ions than pure water Acidic solutions contain higher concentrations of H+ ions than pure water pH value 1- 6 pH value 1- 6

Bases Basic or alkaline solutions contain lower concentrations of H+ ions pure water Basic or alkaline solutions contain lower concentrations of H+ ions pure water Bases have pH values Bases have pH values

Properties of water - Freezing Water freezes at 32 degrees Fahrenheit Water freezes at 32 degrees Fahrenheit Water boils at 212 degrees Fahrenheit Water boils at 212 degrees Fahrenheit Water freezes at 0 degrees Celsius Water freezes at 0 degrees Celsius Water boils at 100 degrees Celsius Water 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 liquid form, which is why it floats In its solid form (ice) it is less dense than the liquid form, which is why it floats

Water Properties – Specific Heat Water has a high specific heat Water has a high specific heat This means water can absorb a lot of heat BEFORE it gets hot This means water can absorb a lot of heat BEFORE it gets hot It helps regulate the rate at which air changes temperature It helps regulate the rate at which air changes temperature This is why the temperature change between seasons is gradual rather than sudden – especially the oceans This is why the temperature change between seasons is gradual rather than sudden – especially the oceans

Water Properties – Surface Tension Water has a very high surface tension Water has a very high surface tension In other words it is stick and elastic and tends to clump together in drops rather than spread out in a thin film In other words it is stick and elastic and tends to clump together in drops rather than spread out in a thin film It is this property that is responsible for another property – capillary action It is this property that is responsible for another property – capillary action

Water Property – Capillary Action It occurs because water is sticky It occurs because water is sticky Water molecules stick to each other and to other substances such as glass, cloth, organic tissue, and soil Water molecules stick to each other and to other substances such as glass, cloth, organic tissue, and soil Importance: Importance: Allows water and its dissolved substances through: Allows water and its dissolved substances through: the roots of plants the roots of plants The tiny blood vessels in our body The tiny blood vessels in our body

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 Measurements

Water Temperature Water temperature is not only important to swimmers and fisherman, but also to industries and even fish and algae. A lot of water is used for cooling purposes in power plants that generate electricity. They need cool water to start with, and they generally release warmer water back to the environment. Water temperature is not only important to swimmers and fisherman, but also to industries and even fish and algae. A lot of water is used for cooling purposes in power plants that generate electricity. They need cool water to start with, and they generally release warmer water back to the environment. The temperature also can affect the ability of water to hold oxygen as well as the ability of organisms to resist certain pollutants. The temperature also can affect the ability of water to hold oxygen as well as the ability of organisms to resist certain pollutants.

pH pH is a measure of how acidic/basic water is. pH is a measure of how acidic/basic water is. Pollution can change a water’s pH, which in turn can harm animals and plants living in the water. Pollution can change a water’s pH, which in turn can harm animals and plants living in the water.

Turbidity Measures the amount of particulate matter that is suspended in water. Measures the amount of particulate matter that is suspended in water. Materials that can cause turbidity are Materials that can cause turbidity are Clay Clay Silt Silt Plankton/microscopic organisms Plankton/microscopic organisms

Ammonia One of the most common aquatic pollutants is ammonia. One of the most common aquatic pollutants is ammonia. It is discharged from industrial, municipal and agricultural wastewater. It is discharged from industrial, municipal and agricultural wastewater. Ammonia is a major component of urine Ammonia is a major component of urine Ammonia is extremely toxic to aquatic life and is an oxygen demanding substance. Ammonia is extremely toxic to aquatic life and is an oxygen demanding substance. Exposure to chronic levels over a long period is more susceptible to disease, reduced reproduction and growth Exposure to chronic levels over a long period is more susceptible to disease, reduced reproduction and growth

Nitrite/Nitrate Ammonia, nitrite and nitrate are related by the process of nitrification, which is the oxidation of ammonia and nitrate Ammonia, nitrite and nitrate are related by the process of nitrification, which is the oxidation of ammonia and nitrate In the presence of oxygen, ammonia is oxidized by Nitrosomonas bacteria to nitrite In the presence of oxygen, ammonia is oxidized by Nitrosomonas bacteria to nitrite Nitrite is then oxidized by Nitrobacter bacteria to form nitrate Nitrite is then oxidized by Nitrobacter bacteria to form nitrate

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

Chlorine Chlorine is a chronic source of stress on the aquatic environment. Chlorine is a chronic source of stress on the aquatic environment. Free and combined chlorine are extremely toxic to fish. Any chlorine is not considered safe for fish. Free and combined chlorine are extremely toxic to fish. Any chlorine is not considered safe for fish. The main source of chlorine in fresh water is domestic wastewater and industry The main source of chlorine in fresh water is domestic wastewater and industry

Dissolved Oxygen Dissolved oxygen is need by fish and zooplankton to survive. Dissolved oxygen is need by fish and zooplankton to survive. Rapidly moving water contains large amounts of dissolved oxygen. Rapidly moving water contains large amounts of dissolved oxygen. Stagnant water contains little dissolved oxygen. Stagnant water contains little dissolved oxygen.

Dissolved Oxygen and Algae Blooms Oxygen depletion due to algae blooms is a common problem in aquatic environments. Oxygen depletion due to algae blooms is a common problem in aquatic environments. When the algae die, bacteria start to decompose them and in the process use up the oxygen. When the algae die, bacteria start to decompose them and in the process use up the oxygen.