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? 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 - Instant pancake mix Kool-aid - 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