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Water

Water. By Señora Ettinger Biology. What do you know about water?. How many brands of bottled water are for sale in the USA?. ~800 brands. How much water is on the Earth’s surface?.

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Water

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  1. Water By Señora Ettinger Biology

  2. What do you know about water?

  3. How many brands of bottled water are for sale in the USA? • ~800 brands

  4. How much water is on the Earth’s surface? • 97% of the Earth’s water is ocean. Tow percent of the earth’s water is frozen in glaciers. One percent is fresh water for us to use!! • The average American uses about 100 gallons of water a day. • A shower, bathroom faucet, toilet and sink use two to five gallons a minute.

  5. How much water was thereon Earth when it formed? • There is the exact amount of water on Earth today as when the Earth was formed. Water is never totally consumed. It always recycles itself, in one form or another.

  6. How much water in your brain? • The average human brain is two thirds water • Trees are also two thirds water.

  7. Water and elephants • Elephants can smell water up to 3 miles away. • Also, a dog’s nose is so sensitive that it can tell the difference between a tub of water with a teaspoon of salt in it.

  8. Water and frogs… • If you drop a frog into boiling water it will hop straight back out again, but if you put it in cold water and heat it slowly the frog will boil to death.

  9. How much water in your body? • Humans are approximately 60% water by weight and 75% water by volume.  As much as 95% of the weight of some plants is due to the water they contain.

  10. Water Formula: H2O: Hydrogen is held to oxygen by hydrogen bonds.

  11. What are hydrogen bonds? • Hydrogen bonds: Weak covalent bonds specific for hydrogen.

  12. Water is a polar molecule.  This is an extremely important property of water.

  13. What is polarity? • Polarity: A molecule in which the charges are unevenly distributed causing the molecule to have poles.  Ex. A magnet

  14. Why is water a polar molecule? • Water is a polar molecule because the oxygen atom contains 8 protons in its nucleus and therefore has a much stronger attraction for electrons than does the hydrogen atom containing a single proton in its nucleus.

  15. How is water unique? • Hydrogen Bonding: water molecules are attracted to each other forming multiple hydrogen bonds between the oxygen of one water molecule and the hydrogen of another water molecule. 

  16. This unequal distribution of charge causes the oxygen end to become negatively charged and the hydrogen ends to become positively charged.

  17. How can this happen?

  18. Polarity and hydrogen bonding of water causes many unique properties: • 1.Cohesion: An attraction between molecules of the same substance causing molecules on the surface of water to be drawn inward. • Ex. Surface tension of insects walking on water and water forming droplets on smooth surfaces.

  19. Another uniqueness of water: • 2.Adhesion: An attraction between molecules of different substances.  • Ex. Capillary action of water being drawn up the roots of plants into the stems and leaves and the capillary action of water being drawn up a small glass tube.

  20. Water can make solutions: • Solutions:  Formed by the polar attraction of water between ionic and other polar molecules.  Water is able to dissolve other polar and ionic compounds when mixed by causing the ions to break away and surrounding them. 

  21.   4.  Suspensions: Some materials do not dissolve in water when mixed but can separate into small pieces that do not always settle out.  Ex. Blood which contains water and many cells and other molecules and sugar water.

  22. Another characteristic: • 5. High Boiling Point: Water will boil at 100oC or 212oF

  23. Solvent: Substance in which a solute is dissolved to make a solution • Solute: substance that is dissolved in a mixture • Acids: a substance that releases hydrogen ions H+ in solution • Bases: a compound that releases hydroxide ions HO- in solution

  24. Neutralization Reaction: chemical reaction that occurs when hydrogen ions of a strong acid react with the hydroxide ions of a strong base to form water and a salt. • PH scale: indicates the relative concentrations of these two ions (H+ & OH-)

  25. Suspension: mixture containing un-dissolved particles distributed within a solid, liquid, or gas. • Inorganic Compounds: Usually compounds that do not contain carbon • Organic Compounds: carbon containing compounds • Polymerization: process by which large compounds are constructed by joining smaller compounds

  26. Monomers: a small molecule that may become chemically bonded to other monomers to form a polymer. • Polymer: large compounds formed by combinations of monomers • Macromolecules: large polymers

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