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| WHAT are the properties of water? | density, polarity, adhesion, cohesion, capillary action, high specific heat, high boiling point, good solvent |
| WHAT makes water a good medium for life processes? | Since water is a good solvent (ions and polar molecules can dissolve in it). |
| WHAT is the pH range for a substance that is acidic? | Acidic substances are a pH of 0-6. |
| WHAT is the pH range for a substance that is basic? | Basic substances are a pH of 8-14. |
| WHAT is the pH range for a substance that is neutral? | Water is neutral with a pH of 7. |
| Explain polarity. | When electrons are not shared equally in a covalent bond, the molecule is described as polar. This means that while water molecules are neutral as a whole, one end of the water molecule tends to have a positive charge while the other has a negative charge. |
| How is polarity related to surface tension? | Cohesion of water also causes surface tension, water's invisible skin which allows water striders to walk on water |
| What does soap do to the surface tension of water? | Soap breaks a part the bonds holding the water molecule together and destroys water's cohesive property. |
| What is the difference between adhesion and cohesion? | Cohesion is the attraction of like substances and adhesion is the attraction of unlike substances. |
| Explain how detergents are related to eutrophication? | Eutrophication, is set in motion when excessive amounts of phosphates and nitrates enter the natural ecosystem. Some sources of these dissolved nutrients include raw sewage, fertilizer run off, detergents, and animal wastes. |
| How is polarity related to capillary action? | Since water is polar, the cohesion of water causes capillary attraction, the ability of water to move uphill in small spaces. |
| Give two examples of places where water moves upward by capillary | Water will move up the fibers of a plant because of cohesion. This force helps plants get the water they need to survive. In addition, it moves water upwards in soil. |
| Using your understanding of capillary action, explain how synthetic | Wicking fabrics transfer water somewhere else, without absorbing it. All wicking fabrics rely on capillary action, often combined with water repelling coatings of the fibers. In addition, Gore-tex having micro-pores, holes too small to allow liquid water in, but large enough to allow water vapor out. |
| Why does water rise higher in thinner capillary tubes? | A thinner tube has less surface area and so the water molecules have less space to fill and that's why they rise higher in a thin tube then a thick tube. |
| How does polarity affect solubility? | Because water is cohesive, water is considered the "universal solvent", able to dissolve a wide variety of substances. |
| Give examples of nutrients that are dissolved in lakes, rivers, and | Nitrates and phosphorous are some nutrients that are dissolved in lakes and rivers. |
| Describe a soap molecule's ability to dissolve water and oil. | The polar end of the soap molecule dissolves in the water while the non-polar end dissolves in the oil. |
| Describe the phase changes that occur in the water cycle. | Water lands on earth in the form of precipitation. Water run-offs into the oceans where it evaporates in the atmosphere. In the atmosphere, water condenses and returns to earth as precipitation. |
| How does freezing water contribute to the weathering of rocks? | When water is trapped in small cracks in rocks, it will expand as it freezes and break up the rock causing weathering. |
| Define density. | The mass per unit volume of a substance at a specified pressure and temperature. |
| How does density affect ocean currents? | When ice freezes near the poles, the salt concentrates in the liquid water of the ocean. The remaining water becomes more salty and therefore more dense. The dense, salty water sinks deep into the ocean and creates a current. |
| How does a fish's swim bladder affect its ability to change depths? | Most fish have a swim bladder, a special sac that is filled with gases from their blood. When the fish's swim bladder is full, it is less dense than the surrounding water and the fish will rise towards the surface. |
| Why does ice float? | Water is less dense in its solid form than in its liquid form, hence a solid that floats! |
| In which phase is water the most dense? | Water is most dense as a liquid. |
| In which phase is water the least dense? | Water is less dense as a solid. |
