Did You Know? Because the architecture and chemistry of coral is so similar to human bone, coral has been used to replace bone grafts in helping human bone to heal quickly and cleanly.

Did You Know? Antarctica has as much ice as the Atlantic Ocean has water. Each year, three times as much rubbish is dumped into the world's oceans as the weight of fish caught

Chapter 8 Questions ISN pg. 37 Text Pg. 8-9 Complete study questions 1-9 Text pg. 8-22 read Ocean Acidification and answer the following questions: 1. Based on the reading, what is the major concern of scientists in recent years regarding ocean acidification? 2. What evidence are they using to validate these concerns? TODAY is your only day in class to work on these!

Goal: Explain water’s chemical bonds. Notes: ISN 23 Seawater Goal: Explain water’s chemical bonds. Notes: ISN 23

The Water Budget Evaporation Condensation Precipitation Transpiration Ocean- 97% of all water on Earth Determines Sea Level Has changed in the last 12,000 years (last Ice Age)

Covalent Bond between oxygen and hydrogen The hydrogen and oxygen are held together by sharing electrons. This is called a covalent bond.

Polar (dipolar) molecule The hydrogen end has a positive charge and the oxygen end has a negative charge. This allows water to bond with other water molecules via hydrogen bonds

HYDROGEN BONDS The negative oxygen side of a water molecule is attracted to the positive hydrogen side of another molecule. This holds water together.

STRENGTH OF HYDROGEN BONDS Extraordinary Properties that are a result of hydrogen bonds. Cohesive behavior Resists changes in temperature Expands when it freezes Versatile solvent The hydrogen bonds joining water molecules are weak, about 1/20th as strong as covalent bonds. They form, break, and reform with great frequency

Seawater is a Homogeneous Solution Solution – molecules of one substance are evenly dispersed among the molecules of another substance. WATER IS THE UNIVERSAL SOLVENT (many substances can dissolve into water) Homogeneous – uniform in appearance. As opposed to heterogeneous mixture (not uniform and made of visibly different materials.

What is the composition of ocean water? Water (Solvent) (96.5%) + Dissolved substances (Solute)(3.5%) = Product (Solution) NaCl is Sodium Chloride= Salt Dipolar water dissociates easily and is Attracted to the positive & negative charge of H2O

Viscosity- The tendency for a fluid to resist flow. Hydrogen bonding of water molecules make water more viscous than it would otherwise be.

strong, flexible “skin” over water surface caused by cohesion Surface tension – water’s resistance to objects attempting to penetrate its surface. strong, flexible “skin” over water surface caused by cohesion What would happen if soap was added the this water The soap would break the bonds that cause surface tension & the insect would fall in the water

Cohesion (Review) Def. – the property of water molecules being attracted to EACH OTHER. (Water molecules stick to one another) Causes surface tension (how water stays in a drop if you put it on the table instead of spreading out) Makes a skin-like surface over the water (surface tension) Also helps the water go up the capillary tube by pulling the others along.

Adhesion (Review) Definition – the property of water molecules being attracted to OTHER types of molecules. Causes “capillary action” The ability of water to crawl up a very skinny tube. This is because the water molecules are being attracted to the molecules of the glass tube.

Specific Heat is the amount of heat that must be absorbed or lost for one gram of a substance to change its temperature by 1oC. Three-fourths of the earth is covered by water. The water serves as a large heat sink responsible for: Prevention of temperature fluctuations that are outside the range suitable for life. Coastal areas having a mild climate A stable marine environment

Temperature Limiting factor for the existence & behavior of living things Most thrive between 0ºC and 30ºC Thermocline- a subsurface zone of rapid temperature decrease w/ depth ~ 1ºC/meter

Density- mass/volume Above 4ºC-Density increases w/ decreasing Temperature 4ºC & below- reverses At 0ºC molecules form a crystal structure- Ice Floats!!!!

Factors Affecting Water Density Turbidity: measure of how cloudy water is. As turbidity increases, density also increases. Adding materials to water increases mass without increasing volume – therefore density increases. Salinity increase or Temp decrease =Density increase

What is the pycnocline? The thermocline and halocline together make a zone in which density increases with increasing depth.

What is the Halocline? High salinity salt waters deep in the ocean.

Salinity Measured in parts per thousand (º/oo) Seawater ~35º/oo How do you figure out the percent of salt? Divide ppt by 10 & you get the percent. Soooo…. What is the percent salt of ocean water on average? 3.5%

Buoyancy Remember our boat lab??? Buoyancy - the upward force on an object in a fluid that is equal to the weight of the displaced fluid.

Pressure 1 atmosphere (atm) at sea level Increase 1 atm for every 10 meters increase in depth Solubility of dissolved gases increases w/ decreased temperature Nitrogen Carbon dioxide Oxygen

http://www. youtube. com/watch http://www.youtube.com/watch?v=0B0EhuxJsts&safety_mode=true&persist_safety_mode=1&safe=active http://www.youtube.com/watch?v=cEnJITnn_4U&safety_mode=true&persist_safety_mode=1&safe=active

O2 pH Concentration influences marine life Transfer occurs: At surface from atmosphere Through Photosynthesis pH Ocean water- Slightly basic Scale:1-14-------7 is neutral Low pH-Acidic (High H+ concentration) High pH-Alkaline (Low H+ concentration)

Colligative Properties of Seawater Colligative properties – Properties of a liquid that may be altered by the presence of a solute.

Colligative properties of seawater Raised boiling point Decreased freezing temperature Ability to create osmotic pressure Electrically conductive Slowed evaporation – seawater evaporates more slowly than fresh water

Photic zone Depths determined by how rapidly seawater absorbs light & converts it to heat energy Influences Dissolved substances Suspended sediments Plankton population

What is the difference between osmosis and diffusion? Diffusion – movement from high concentration to low concentration. Heat speeds up diffusion. Osmosis – diffusion through a semipermeable cell membrane. Water moves through the cell from high concentration of water to lower concentration of water.

Osmosis & Diffusion Diffusion Osmosis Write the definitions. http://www.youtube.com/watch?v=STLAJH7_zkY&feature=related&safety_mode=true&persist_safety_mode=1&safe=active http://www.youtube.com/watch?v=6Rd2bEp380w&feature=related&safety_mode=true&persist_safety_mode=1&safe=active Osmosis Write the definitions.

What types of solutions Are these? Watch the clip and think salinity instead of tonicity. Hypotonic Isotonic Hypertonic http://www.youtube.com/watch?v=6MWl3DCa2uM&safe=active

Osmoregulators – organisms with the ability to adapt to sur- rounding salinity changes

Active Transport vs. Passive Transport. Passive transport does not require energy (example: osmosis) Which requires energy? Active Osmoregulators would use which of the following? Active transport

Did You Know? Each person sheds 40lbs of skin in his or her lifetime

Vocab. put in your own words. ISN 20 Vocab. put in your own words. 1.Adhesion 2. Cohesion 3. Density (what effects it?) 4.Dipolar (8-6) 5. Halocline 6.Hydrogen bonding 7.Surface tension 8.Thermocline 9.Viscosity 10. Salinity 11.Parts per Thousand 12. Covalent Bonding 13. Homogenous mixture 14. Heterogeneous mixture 15. Dissociation 16. Pycnocline 17. Ionic bond 18. Brackish water 19. Colligative properties

Mini-Summative REminders You will need a separate sheet of paper for this. All stuff closed up and pushed to the front of the desk or on the floor. No electronics When you finish this on just turn it over please.

Vocabulary Quiz 1. Water molecules sticking to each other is known as ____________. 2. _____ _______ is the reason some small bugs can literally walk on water. 3. _________ is the hydrogen bonding of water molecules that resist forces. 4. Water molecules sticking to things other than each other is called ___________.

Vocabulary Quiz 5. 35 ‰ means that in 1,000 units of seawater I have 35 units of salt. What is this called_____? 6. The _________ can change if you change the mass. 7. Water is a _______ molecule because it has two positive hydrogen poles and a negative O2 pole.

Vocabulary Quiz 8. A _________ is an abrupt change in salinity that marks two different water layers. 9. A _________ is a transition between a colder, deeper water layer and a warmer upper water layer. 10. ____________ bonding is the type that is formed between water molecules. 11. Studying lakes would be freshwater biology, unlike _________ biology which deals with saltwater.

Water Lab Reflection Questions! 1. Which liquid had the most adhesion? Why? 2. Which liquid had the lowest rate of evaporation? Which was the highest? 3. Which liquid had the least cohesion? 4. How do the cohesion and rate of evap. compare? 5. What is solvency? 6. Which was a better test for solvency? The sugar or food coloring? Why?

Use the text or your technology to define these in your own words! Endotherm Ectotherm

The Therms… Ectotherm: temp varies… Endotherm: temp varies but constantly higher than surrounding. Poikilotherm: Large fish or reptiles that vary but are higher than surrounding. Homeotherm: constant temp. (mammals)

Under Pressure! For every 10 m or 33 ft add 1 atmosphere of pressure. Hydrostatic pressure: doesn’t affect many marine animals due to the liquid in their bodies. Liquid doesn’t compress.