Properties of Water Water covers 23 of Earth
- Slides: 29
Properties of Water
Water covers 2/3 of Earth • 97% Saltwater oceans • 2. 4% Ice (polar caps and glaciers) • 0. 6% Surface water (lakes and streams)
The Human body is made of ~80% water. • To function properly, the body requires between one and seven liters of water per day to avoid dehydration; the precise amount depends on the level of activity, temperature, humidity, and other factors. • Most of this is ingested through foods or beverages other than drinking straight water.
Properties of Water is polar …. Remember…. Water has 2 hydrogen atoms and one oxygen atom H 2 O _ (–) Hydrogen bond (+) H O H + (+) H O (–) H (–) (+) (–) + (+)
Properties of Water cohesion adhesion High specific heat density p. H
Cohesion • The natural attraction of a water molecule to other water molecule is called cohesion.
Adhesion • The attraction of a water molecule to another polar molecule is adhesion. water droplets on a spider’s web (polar surface).
Properties associated with polarity/ adhesion, cohesion • Capillary Action • Surface Tension • Transpiration
Capillary Action
Surface Tension • At the surface of the drop of water, water does not attract to the air…. . Surface tension
Jesus Lizard
Transpiration
Properties of Water cohesion adhesion density High specific heat p. H
Density
Why is “ice floats” important? ? § if ice sank…. . o eventually all ponds, lakes, and even ocean would freeze solid o during summer, only upper few inches would thaw § surface insulates water below o allowing life to survive the winter
Properties of Water cohesion adhesion density High specific heat p. H
An example is the more moderate climate of a coastal location compared to one far inland.
Properties of Water cohesion adhesion density High specific heat p. H
p. H 0 More acidic…more H ions neutral p. H 7 water More basic…more OH ions p. H 14 Most biological fluids have a p. H b/w 6 and 8 …. But stomach can reach a p. H of 2
Properties of Water cohesion adhesion density High specific heat p. H