Water’s Unique Properties
What is the structure of water?
• Water is a compound that contains two hydrogen
atoms (+) and one oxygen atom (-). Due to the
electrical charges water is known as a polar
molecule. Chemical formula is H2O.
• Looks like Mickey Mouse.
Turn and Talk
• You will partner with your neighbor. When I say go, partner
A will discuss his/her understanding of the question while
partner B listens. When I call time, partner B will share
his/her understanding of the question and partner A will
listen.
– Topic:
• Why does ice float?
• How does ice floating in water relate to the properties
of water?
• What property of water is being discussed? How
would our world be different without this property?
What are the unique properties of
water?
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Universal Solvent
Capillary Action
Adhesion
Buoyancy
Surface Tension
Polarity
Cohesion
Density
How is water a universal solvent?
Answer: Water has the ability to dissolve most substances.
Definition:
- Universal Solvent: Water’s unique property to dissolve
most substances.
Teacher Guided Lab: “Water, the Universal Solvent”
Real-World Examples:
- Salt and water
- Kool-aid
- Instant pancake mix
- Alka-seltzer
Question (copy): How would our lives be different if water
could not dissolve most substances?
Frayer Model: Think-Pair-Share
Is water polar or nonpolar?
Answer: Water is a polar molecule. It contains a positive and negative
charge.
Definition:
- Water’s property to have an even distribution of charge across
the molecule.
Background Info:
- Polar molecule mix with polar molecule. (saltwater)
- Polar and nonpolar do not mix. ( oil and water)
- Nonpolar mix with nonpolar. (milk and chocolate
syrup)
Teacher Guided Lab: “Polar Pals”
Quesion (Copy): How would our food look different if water was not a
polar molecule?
Frayer Model: Think-Pair-Shar
Why do belly flops hurt?
Answer: When entering a swimming pool your body is breaking the
water’s surface tension.
Definition:
- The force that acts on the particles in water that allow it to become tight.
Background Info:
- The force that allows water to become tight is cohesion.
- Cohesion: The attractive force between water molecules.
Teacher Guided Lab: Sinkin’ Lincoln
Question: How would the landscape of Earth be different if water
molecules did not have cohesion and vaporized at room
temperature?
Frayer Models: (Surface Tension, Cohesion) Think-Pair-Share
How do cruise ships float if they are so
big?
Answer: Cruise ships are able to float because of the upward force of buoyancy and
the boats shape.
Definition:
- Buoyancy: The ability of a water to exert an upward force on an object that is
immersed.
Background Info.:
-
Density of water is 1.0 g/ml
Salt and depth increase buoyant
force.
Real-World Examples:
- Salt Lake Utah
- Ice floating in water
Teacher Guided Lab: “Passengers in a Boat”
Question: Why can anyone float in the
Great Salt Lake in Utah?
Frayer Model: Think-Pair- Share
Bowling ball. Sink or float? Why?
Answer: A bowling ball would sink in water because it is more
dense than the water.
Definition:
Density: The measure of mass of a substance in a given volume.
Background Info.:
- Density of water= 1.0 g/ml
Teacher Guided Lab: “A Density Column”
Frayer Model: Think-Pair-Share
How do plant roots get their water
from the soil?
Answer: Plants roots rely on water’s property of capillary action.
Definition:
Capillary Action: The process that moves water through a narrow porous
space.
Real-World Ex.
- Water and celery stick (picture)
- Roots and soil water
- Paper towel and spills
Teacher Guided Lab:
- Capillary Action
Frayer Model: Think-Pair -Share
Why does a suction cup stick better
when you put water on it?
Answer: Suction cups use water’s property of adhesion to stick
to surfaces better.
Definition:
Adhesion: The tendency of water to stick to other substances.
Real-World Examples:
- Suction cup on a window
- Rain on a rain jacket
Teacher Guided Lab: Go with the Flow
Frayer Model: Adhesion