2 Do Now1. How do we rely or use water in our everyday life? 2. Why is water so valuable?
3 Do Now1. Why were our results so scattered yesterday? 2. When we repeat the penny water/isopropanol today, what would you do differently? 3. Take out your investigating water properties handout.
4 Do Now What is chemical formula for water? What does a water molecule look like? Draw one.List one property of water from the reading that makes it unique.
5 ObjectivesSWBAT identify unique properties of water by performing a water activity and then discussing the resultsSWBAT define properties of adhesion, cohesion, polar, nonpolar, and hydrophobic/hydrophillic of water and relate it water activity
6 Water ActivityHow many drops of water can you place on the surface of a penny? How many drops of isopropanol can you place on the surface of a penny? Use the handout and create a data table and drawing of the penny.
7 What does Water Look like? Let’s draw it! Atom: Molecule: Polar:
8 Water VideoWe can use the properties of water to explain why the large number of drops can be placed on the surface.https://www.youtube.com/watch?v=aVmU3CLxvgU
9 DO NowExplain why the penny makes a dome shape of water in the “drops on a penny” activity.Explain why a drop of isopropanol causes the dome of water to break.
10 ObjectivesSWBAT identify unique properties of water by performing a water activity and then discussing the resultsSWBAT define properties of adhesion, cohesion, polar, nonpolar, and hydrophobic/hydrophillic of water and relate it water activity
12 Water contains hydrogen bonds -Hydrogen bonds are weak bonds between like molecules -Partial positive charge attracts a partial negative charge
13 What forms a drop?-Cohesion causes water to form drops Cohesion: attraction of water to water -Surface tension causes the drops to be spherical -Adhesion keeps the drops in place Adhesion: attraction of water to unlike substance
14 Surface Tension:Water pulls in and attracts itself to form a “film” on its surface to form a drop
15 Water Drop Shapes-Water has cohesion to itself and forms a nice, round drop -Round drop on wax paper (not strong adhesion to water) -As adhesion to glass is stronger and pulls the water, it makes a flatter drop
18 Water coheres to polar, not nonpolar -“Like adheres to Like” -Polar molecules will attach to polar and nonpolar will attach to nonpolar -Water (polar) has no adhesion to wax paper (nonpolar). It rolls right off.
19 Do NowExplain how to make water not form a drop on a piece of wax. Explain what happens on the molecular level.
20 Objectives1. SWBAT continue identify, explain, and apply the properties of water and how they apply to water lab using the water lab.2. SWBAT define hydrophillic, hydrophobic, capillary action, and specific heat and apply it to how water is essential to keeping organisms alive using questioning and the chapter 2 powerpoint.3. SWBAT answer questions on the properties of water using chapter 2 worksheet.
21 Capillary action: water climbs up small spaces Because water has both adhesive and cohesive properties, capillary action is present.Capillary Action = water’s adhesive property is the cause of capillary action. Water is attracted to some other material and then through cohesion, other water molecules move too as a result of the original adhesion.Ex: Think water in a strawEx: Water moves through trees this way
22 Adhesion to glass and cohesion of water to water
24 Hydrophobic and hydrophilic -Oil is hydrophobic meaning it does not mix with water. -Oil is nonpolar and has no hydrogen bonds -Water is polar and hydrophilic. - Remember: Like dissolves Like!Food coloring in waterOil in water
26 Water is the Universal Solvent Solute: substance that is dissolved Solvent: agent that does the dissolving Solution: Solute dissolved in solvent Properties of water that make it an excellent solvent: -water is polar and can dissolve polar and ionic molecules
28 Specific Heat of Water-Due to hydrogen bonds, water has a better ability to resist temperature change as compared to other substances -Energy (Heat) must be absorbed to break hydrogen bonds -Energy is released when hydrogen bonds are formed Video Relation to Biology: -How does this relate to biology?
29 Specific Heat& Life Relation to Biology: -Large bodies of water have a fairly constant temperature compared to the atmosphere-Keeps the water within limits to supply life!-Your body is made of 66% water… homeostasis-Coastal areas generally have milder climates-Large water (oceans) bodies can absorb and release heat-Heat is absorbed from the sun during warmer times and releasedduring cooler times to warm the air
30 Water Density-Ice is less dense than water -Water vapor is less dense then water Relation to Biology: -If ice sank, then lakes and rivers would freeze -Killing the aquatic life
31 Water Pollution Why is water important in biology? https://www.youtube.com/watch?v=fxZ4IMpM45Y
32 Oil Sheen-Oil Sheen on water -Oil on top of water in a thin layer Pollution: How doe we get rid of it?
33 How to get rid of oil on water -Detergent breaks up oil into small drops -Detergents are amphipathic have both polar and nonpolar regions