Presentation on theme: "Water Chemistry A polar molecule (small + charge/ - charge) Cohesion (water sticks together to form drops and surface tension) Adhesion (water sticks to."— Presentation transcript:
Water Chemistry A polar molecule (small + charge/ - charge) Cohesion (water sticks together to form drops and surface tension) Adhesion (water sticks to polar substances) High specific heat (hard to cool down or heat up High heat of vaporization (large amts. Of energy needed to evaporate) Solid less dense than liquid (ice floats)
Why sweating is so effective in cooling the body. The high heat of vaporization means that a great deal of energy is taken from the skin to evaporate the sweat.
Why plasma so effectively carries waste, minerals, vitamins and salts to various parts of the body. The solubility of water allows many substances to dissolve and then be carried. Also allows for lakes, streams, oceans… to carry nitrates, phosphates and other testable substances.
Why can fish live in northern lakes? When the temperature reaches freezing and the top layer of the lake becomes ice it floats. Otherwise the lake would become solid ice and all live would die. Insulates too.
How does water rise up the xylem in plant stems? First, capillary action causes water to stick to the side of the tubes and then water is pulled up due to cohesive forces. This moves water up small distances. Second, for larger distances transpiration allows water to evaporate from the leaf and pulling water up to replace the leaving molecules. (cohesion/transpiration combination)
Why does the temperature of the Earth fluctuate in small amounts? Water heats up and cools down slowly due to high specific heat, so this keeps the Earth from having wild changes in temperature. Islands (Hawaii has little change in temperature)
Why does a belly flop hurt? Surface tension is the resistance to an object entering a liquid due to the “skin” formed by the attraction of like molecules
Why don’t plankton do well in tropical “clear” waters? As the temperature of water slowly changes during a season, it reaches a point where the density of the water on the top and bottom of the body of water is different enough that they turnover. This brings large amounts of nutrients up from the bottom to feed plankton