1. O - - - - - - - - H - H - Water (H 2 O) Water is a polar molecule This means that... A.All atoms have equal electrical charges B.A water molecule is linear, like a pole C.The opposite ends of the molecule have opposite electrical charges D.Water is hydrophobic

2. Water is a polar molecule

3. O - - - - - - - - H - H - Water (H 2 O) Non-polar: electrons are shared equally among atoms Polar: electrons are NOT shared equally among atoms

4. Hydrogen bond – a WEAK bond that forms between a Hydrogen atom in one molecule and an atom in another molecule

5. Web animation

7. Polar molecules dissolve in water Hydrophilic = water loving

8. Ion – an atom that has gained or lost an electron 17 e - 11 e -

9. Ion – an atom that has gained or lost an electron Ionic bond – attraction between two oppositely charged ions

11. Water and sugar demo

12. Sugar (glucose) dissolves in water because it is... A.an ionic compound. B.a polar molecule and forms many hydrogen bonds with water molecules. C.a very unstable molecule. D.highly non-polar.

13. Glucose C 6 H 12 O 6 -

14. Types of Chemical Bonds Covalent bond = atoms share electrons VERY STRONG Ionic bond = (+) atoms attracted to (-) atoms WEAKER Hydrogen bond = Partial (+) attracted to Partial (–) WEAKEST

15. pg. 42

16. What type of bond is indicated by the arrow? A.Hydrogen bond B.Covalent bond C.Ionic bond D.Hydrophobic bond

17. Covalent bond

18. Properties of water 1.Cohesion – water molecules stick together

19. Properties of water 1.Cohesion – water molecules stick together 2.Large heat capacity

20. Properties of water 1.Cohesion – water molecules stick together 2.Large heat capacity 3.Low density as a solid

21. Properties of water 1.Cohesion – water molecules stick together 2.Large heat capacity 3.Low density as a solid 4.Good solvent Human circulatory system displayed at the Bodies exhibit

22. Water has so many unique properties because.... A.of the covalent bonds between the oxygen and hydrogen. B.of its ability to hydrogen bond. C.of its ability to make and break ionic bonds. D.the electrons are shared equally between the oxygen and hydrogen atoms.

23. The abundance of water is a major reason why there is life on Earth WATER FOR LIFE

24. Water!!! Water is a polar molecule that easily forms hydrogen bonds. Because of this, it has four characteristics that has allowed life exist on Earth

25. Water’s Life Supporting Properties Cohesion: Water’s polarity causes it to form Hydrogen bonds with itself, so the molecules stick together –Called Cohesion This allows water to travel up tree roots into trees, and gives water surface tension, which allows things to “stand” on top of water

27. Water’s Life Supporting Properties Water’s High Specific Heat: Specific Heat: The amount of energy needed to raise 1 gram of a substance 1 degree Celcius Water has a very high specific heat!!! This is because its hydrogen bonds absorb lots of heat Water covering the Earth regulates the Earth’s temperature, keeping in the liveable range

28. Water’s Life Supporting Properties Ice is Less Dense than Water: When water freezes, it forms a lattice that makes it less dense than water –Less molecules in the same volume –Most solids are denser than liquids THIS MAKES ICE FLOAT!!! Ice floating allows only the tops of water bodies to freeze, thus not killing all life

29. Hydrogen bond Ice Hydrogen bonds are stable Liquid water Hydrogen bonds constantly break and re-form

30. Hydrogen bond Ice Hydrogen bonds are stable Liquid water Hydrogen bonds constantly break and re-form ICE Because only the top freezes, the living things underneath don’t freeze to death

31. Water’s Life Supporting Properties Water is the Universal Solvent: Solution: A homogenous mixture of two or more substances –Solvent: Dissolving agent, Solute: What is dissolved –Aqueous Solution: A solution where water is the solvent Because water is polar, atom with a charge or ionically bonded compound will dissolve in it This allows all living things (which are water based), to dissolve the variety of compounds they need for life –Example: Cells, blood, tree sap, etc…

32. Ion in solution Salt crystal

33. Bellringer What are the 2 types of bonds? Draw me the Lewis Dot structure of 2 hydrogen atoms

34. Agenda Objective: To begin bonding practice Agenda: –Bellringer/Discussion –Grade Atom WS –Practice Bonding –Go over rubric for tomorrow Homework: –Bonding write-up due Tuesday

35. Molecule Models Every group needs one bag of model materials –The circles with pegs are atoms –The bendy plastic pieces are bonds Each peg represents a bond that atom can make Based on what you know about the number of valence electrons each atom has, tell me which atoms you have are Hydrogen, Oxygen, and Carbon Everyone must write this on their own sheet

36. Molecule Models Make Models of the following Molecules: H 2, O 2, H 2 O, CO 2, CH 4, C 2 O 2, C 2 OH 2, C 6 H 12 O 6 On your sheet, you must draw the following: Lewis Dot Structures of each atom pre-bonding Line/Lewis Dot Structures post-bonding Label single/double bonds COPY THIS EXAMPLE DOWN!!!

37. Molecule Models Make Models of the following Molecules: H 2, O 2, H 2 O, CO 2, CH 4, C 2 O 2 On your sheet, you must draw the following: Lewis Dot Structures of each atom pre-bonding Line/Lewis Dot Structures post-bonding Label single/double bonds COPY THIS EXAMPLE DOWN!!!

38. Bellringer Study Get out whatever periodic table you are going to use during the quiz

39. Bellringer Name and describe 2 of water’s 4 unique properties that allow life to exist and flourish on Earth Do you like drinking water?

40. Agenda Objective: To start the water mini-lab Agenda: –Bellringer/Discussion –Go over quiz stuff –Go over lab –Lab all period Homework: –Quiz tomorrow –Lab due Monday –Macromolecule Chart due Monday

41. Quiz Atomic Info Bohr Models Lewis Dot Structures Bonding like in the bonding WS

42. Water Mini-Lab Write Up You are going to perform the following tests on water and vinegar 1.How many drops of water/vinegar will fit on top of a penny? 2.Is there cohesion leading to surface tension?(will a staple rest on top of it) 3.Will Kool-Aid dissolve in it (make sure you use same mass/volume of liquid in each) 4.Is there cohesion-travel up thin tubes (celery)?

43. Water Mini-Lab Write Up Make a hypothesis for each test first Make sure you control/record all amounts RECORD ALL PROCEDURE/MATERIALS!!! RECORD ALL DATA FOR GROUP!!! HOMEWORK: –Typed hypothesis, procedure, materials, and data, and conclusion due Tuesday –Should be between 1-3 pages –Conclusion should just be an explanation of whether your hypothesis was supported or not, and why based on data –1 per group