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- 1. Cooperative Learning CLIL: ChemistryWater MoleculeMattayomsuksa 4
2. Video 3. Vocabulary 4. dipolar 5. bond 6. cavalent bond 7. ionic bond 8. dissolve 9. Structure 10. Noun clauseDefinitionA dependent clause that functions as a noun (thatis, as a subject, object, or complement) withina sentence. Also known as a nominal clause.Examples The bonding angle of the two hydrogen is almost 105degrees rather than 180 degrees which would makethe molecule symmetrical. This means that it can absorb or can lose a lot of heatenergy without changing its temperature very much. 11. Water molecule 12. The water molecule is formed from twohydrogen atoms and one oxygen atom. Thebonding angle of the two hydrogens is almost 105degrees rather than 180 degrees which wouldmake the molecule symmetrical. This causes it tobe dipolar, giving it a positive and negative sidewhich accounts for its unique properties. Thisallows the formation of hydrogen bonds betweenadjacent molecules. There is a weakintermolecular force of electrostatic attractionbetween the molecules which is known as van derWaals force. This causes the molecules to act aslarger units than the individual molecules. 13. Water is a very unusual compound; it isvery common and is found in all threeconditional states, solid (as ice), liquid (aswater) and gas (as water vapor). Other typesof bonding can occur, such as covalentbonding (as seen in the formation ofmolecular oxygen) or ionic bonding (as seen inthe formation of salt or sodiumchloride[NaCl]). Hydrogen bonding can breakup the electrical attraction of atoms of solidsand dissolves them. 14. In ice crystals the water molecules arewidely separated, while in the liquid formthey are closer together although less tightlybound. Therefore ice is bulkier and less denseand floats on water. If we compare thefreezing and boiling points of water with whatone would predict from extrapolating themolecular weights of other molecules, we seethat it would be predicted to freeze at -90degrees C and boil at -68 degrees C. What adifferent world we would have. So much forthe validity of extrapolation. 15. The heat capacity of water is high comparedto other common materials. This means that it canabsorb or can lose a lot of heat energy withoutchanging its temperature very much. This buffersthe environment against large, rapid temperaturechanges. An example is the more moderateclimate of a coastal location compared to one farinland. The diel temperature change of the surfacewaters of the oceans (or lakes, or even aswimming pool) is small compared to the dieltemperature change of the surrounding air. This isdue to the high heat capacity of water. 16. Water Molecules on the Move(Test the speed of water molecule with food coloring) 17. This experiment is great for testing if hotwater molecules really move faster than coldones. Pour some water, drop in some foodcoloring and compare results. 18. What youll need A clear glass filled with hot water A clear glass filled with cold water Food coloring An eye dropper 19. Instructions1. Fill the glasses with the same amount of water, one cold and one hot.2. Put one drop of food coloring into both glasses as quickly as possible.3. Watch what happens to the food coloring. 20. Whats happening?If you watch closely you will notice thatthe food coloring spreads faster throughoutthe hot water than in the cold. The moleculesin the hot water move at a fasterrate, spreading the food coloring faster thanthe cold water molecules which mover slower.