1.61k likes | 1.63k Views
Discover the properties of water through hands-on experiments using different materials and concepts. Learn about water distribution, importance of groundwater, and more.
E N D
Water Chapter 11 Environmental Science Spring 2008 Cox
You should have: 1 cup of clean water 1 cup of soapy water 2 pipettes / eye droppers 1 paperclip 1 pinch of black pepper 1 graduated cylinder 1 strip of paper towel 2 pennies 2 squares of wax paper 1 waste water bowl 1 denture tablet WAIT for directions we will walk through the steps together.
Objectives (what you need to learn) • Identify properties of water • Describe the distribution of water on Earth • Explain why water is a limited resource • Identify the local watershed and progression of water to the ocean • Describe the importance of groundwater • Explain how GW is stored and replenished
Watch the video - • How many properties of water can you see being demonstrated in the video?
QUIZ • Draw and label the water molecule. • What is surface tension? • How does specific heat relate to your pool? 4. What is the MENISCUS 5. The temperature range 0-100*C is significant to water. • WHAT does that range represent? • What is that range in degrees Fahrenheit?
Water Structure and Science • Water (H2O) - transparent, odorless, tasteless and ubiquitous. It is the simplest compound of the two most common reactive elements, consisting of just two hydrogen atoms attached to a single oxygen atom.
Properties of water • Hydrogen Bond • High surface tension • High specific heat • Cohesion and Adhesion • Capillary Action • Neutral pH 7 vid • Exists over a range from 0-100* C • Universal Solvent • Polar
Hydrogen Bonding • UNEQUAL sharing of electrons – causes a negative side and a positive side of the water molecule. • Opposites attract – the “pull” created by opposite charges in POLARITY.
High Specific Heat • Specific heat is the amount of energy required to change the temperature of a substance. • Water can absorb large amounts of heat energy before it begins to get hot. • Water releases heat energy slowly when situations cause it to cool. • Water's high specific heat allows for the moderation of the Earth's climate and helps organisms regulate their body temperature more effectively.
Adhesion and Cohesion n • Water is attracted to other water. This is called cohesion. • Water can also be attracted to other materials. This is called adhesion. • Attraction between the charges of H+ and O- atoms causes sticking.
Capillary Action It is defined as the movement of water within the spaces of a porous material due to the forces of adhesion, cohesion, and surface tension.
UNIVERSAL SOLVENT • Eventually ALMOST EVERYTHING will dissolve in water … • Because water is POLAR (having a + side and a – side) it is attracted to other molecules breaking their bonds and pulling them apart.
pH • Water in a pure state has a neutral pH (7). As a result, pure water is neither acidic nor basic. • Water changes its pH when substances are dissolved in it. • Rain has a naturally acidic pH of about 5.6 because it contains natural derived carbon dioxide and sulfur dioxide.
STATES OF WATERExists 0-100ᵒC or.. ?ᵒF GAS SOLID LIQUID
Hydrogen Bonding • UNEQUAL sharing of electrons – causes a negative side and a positive side of the water molecule. • Opposites attract – the “pull” created by opposite charges in POLARITY.
Great Conductor! • Water conducts energy (only because of the salts). • When salts dissolve in water, they form ions (NaCl becomes Na+ and Cl-, for example) and it is these ions that carry charge.
Why does ICE float in water? • ANSWER
DISTRIBUTION OF WATER • DISTRIBUTIOPN OF WATER ON EARTH • WATERSHEDS - PA • DRAINAGE PATTERNS
Objectives (what you need to learn) • Identify properties of water • Describe the distribution of water on Earth • Explain why water is a limited resource • Identify the local watershed and progression of water to the ocean • Describe the importance of groundwater • Explain how GW is stored and replenished
Objectives (what you need to learn) • Identify properties of water • Describe the distribution of water on Earth • Explain why water is a limited resource • Identify the local watershed and progression of water to the ocean • Describe the importance of groundwater • Explain how GW is stored and replenished
Distribution of Water on Earth • 97% Salt • 3% Fresh • 69% Glaciers and Icecaps • 30% Groundwater • 1% (~0.8% OTHER and ~0.2% potable) surface – or otherwise potable (drinkable) • 87% Lakes • 11% Swamps • 2% Rivers
If you threw a note in a bottle… • Where would it go?
Watersheds also known asDrainage Basins • Area of land drained by a river • What watershed are we in ? -Ten Mile -Monongahela -Ohio - Mississippi
PA’s 2 Major Watersheds • West = Mississippi River • East = Chesapeake Bay • Divide – topographic high that creates a barrier (PA = Appalachian Mt.’s)
6 BIG watersheds in PA • Great Lakes Basin • Ohio River Basin • Susquehanna / Chesapeake Basin • Potomac Basin • Delaware Basin • Genesse River
Dendritic • Looks like a tree • Rivers branch randomly • Bedrock is uniform and resistant
Rectangular • Sharp angles • found in regions that have undergone faulting
Trellis • 90* angles • develops in folded topography
Radial • Radiates from the center of a topographic high
STREAM ORDER SOURCE of the river is where it starts. MOUTH – where a River end in a larger body of water.
STREAM ORDER SOURCE of the river is where it starts. MOUTH – where a River end in a larger body of water.
The Earth is calledTHE BLUE PLANET. • WHY? • Because ¾ of it is covered with water
Hydrologic Cycle • Water is a limited renewable resource
THE WATER CYCLE • Evaporation – liquid to gas • Condensation – gas to liquid • (Evapo)Transpiration – Water from living things • Infiltration – Water seeping into ground • Precipitation – Rain • PERCOLATION – slowly passing through a filter.
HW • Read in the text book page 269-275 • DO q’s on page 275 • Then read the case study page 272 do the q’s also.