Water : A Molecule Essential for Life. Thoughts to Ponder……. Why can’t we survive more than a week without water? How do insects walk on water? How does water rise up 300 feet from the roots of a redwood tree? Why does water take so long to boil? Why do oil and water not mix? .
Source: www.personal.psu.edu/.../ bonddiagram.gif.
Water molecules are attracted to different molecules
Capillarity – a special case that results from the relative attraction of the molecules for each other and the solid surface it’s in contact with
A great deal of E is
needed to break
Specific heat – amount of heat needed to change the temperature of 1g. of a substance 1degree Celsius.
High specific heat allows water to act as a heat sink. Water will retain its temperature after absorbing large amounts of heat, and retain its temperature after losing equally large amounts of heat.
The “Great Dissolver”
Water dissolves polar and ionic substances due to its ability to form hydrogen bonds
Water cannot dissolve nonpolar substances.
Hydrophobic effect- results when water molecules interact with each other and exclude nonpolar substances
Causes molecules like DNA to fold into their specific shapes
Ice is less dense then water - it floats
Ponds, lakes, streams, ocean surfaces freeze from the top down.
Aquatic organisms receive insulating protection
Large amounts of heat E are needed to disrupt hydrogen bonds.
Heat helps water to begin evaporating.
Sweat evaporates using the heat from your body…cools your body down!
molecules no longer could form