A Few Ultra Cool Properties!
• The only natural substance found as a liquid, solid, and
gas at temperatures normally found on Earth
• Part of every living organism
• It dissolves nearly everything
The Mickey Mouse Molecule!
Hydrogen
Hydrogen
Oxygen
Structure of a Water Molecule
• Water is polar.
• A polar molecule is a
molecule that has a separation of charge
• Water is made of:
• 2 Hydrogen Atoms and 1 Oxygen atom.
• The chemical formula for water is: H2O
• Hydrogen has a positive (+) charge and Oxygen has a
negative (-) charge.
4 Key Properties of Water
• Capillary Action
• Surface Tension
• Universal Solvent
• Specific Heat
Notes:
The Properties of Water
Capillary Action
• Capillary action is the ability of a liquid to flow up a
small, narrow space (against gravity) due to:
– water molecules stick to themselves = cohesion
– and water molecules sticking to molecules of surrounding
materials = adhesion.
• Examples of Capillary Action of Water:
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Liquid rising inside a straw
Paper towel absorbing water
Wet jeans
Plant roots absorbing water
Sponge
Cohesion and Adhesion working together
Surface Tension
• Surface tension is the tightness across the surface of water that is
caused by the polar molecules pulling on one another
• Examples of the surface tension of water:
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Raindrops forming beads on surface
Water strider
Paperclip Floating on Water
Drops of Water on a Penny
Skipping Rocks
Meniscus
Belly Flops
Jesus Lizard
Water Strider
Universal Solvent
• Water is the universal solvent because it dissolves so
–
many substances because of its high polarity.
Polar Dissolves Polar. (like dissolves like)
• Water dissolves more substance than any other
-
substance
Specific Heat
• Specific heat is the amount of heat
needed to increase the temperature of a
substance by 10C
– Water’s high specific heat is due to the
strong attraction among water
molecules.
– The molecules are stuck together and
it takes a lot of energy to break the
strong bonds of the water molecules
Example of specific heat:
- Water temperature vs. sand temperature at the beach during the day.