Properties of Water

​Properties of Water

• Human bodies are about 60% water

• 50-80% of our oxygen is produced by plankton that lives in the ocean.​

​71% of the Earth's Surface is Water

​

Water is composed of two hydrogens and one oxygen. This structure makes water POLAR.​

POLAR molecules have a partially positive and partially negative charge indicated by δ​+ or δ-

​

​H₂O

​

ADHESION - water is sticky, and will stick to other surfaces. Think an adhesive bandage. It makes the bandage stick to your skin.

​

​

​

​This POLAR structure creates two key characteristics

​

COHESION - water is sticky, and will stick to itself. Like magnets, the two opposite poles are attracted to each other.

​

​

​This POLAR structure creates two key characteristics

​

Multiple Choice

What is adhesion?

• sticking to itself

• sticking to something else

• being repelled from a surface

Fill in the Blanks

Because of the hydrogen bonds that hold water molecules together, water also has surface tension that allows for small things to sit on the surface of the water without falling through.​

​

​

​Surface Tension

​

...also allows for water to overflow in a glass without spilling. Because of the adhesive and cohesive properties, the water sticks to itself rather than spilling over the edge. ​

​

Surface Tension​

​

​Water is able to move upwards, against gravity in small spaces such as fibers in a paper towel, or in xylem (the water transport tissue in plants). The adhesive and cohesive properties allow water to stick to the surfaces material and cohesion allows water molecules to "pull" molecules up.

Capillary Action​

​Liquid water is essential for life. When scientists look for life on other planets they are first looking for liquid water or signs that liquid water was present.

​

​​Liquid

​

​Ice is important for aquatic habitat insulation. It floats because when it freezes it becomes more "organized" and less dense.

​​Solid

​

​Once water has been heated enough (enough energy has been applied) the hydrogen bonds can no longer hold the molecules together and they become vapor.

​​Vapor

​States of Matter

When water freezes, it becomes more organized or crystalline. Because of this it is less dense and float insulating the water underneath.​

​

​Ice Insulates

​

​Because of the POLARITY of water, it is able to dissolve most substances. If you've ever dissolved sugar or salt in a glass of water, you would notice it occurs quickly.

​

​​

​Water is the UNIVERSAL SOLVENT

​Dissolves another substance (SOLUTE) to create a solution

Usually a liquid, but not always​

​​SOLVENT

​

​Material that is dissolved by a SOLVENT to become a solution.

​​SOLUTE

​

Multiple Choice

What is this an example of?

• How light paper clips are

• bouyancy

• surface tension

• cohesion

Match

Match the following

Solid

Liquid

Vapor

• Solid

• Liquid

• Vapor

​H₂O + CO₂ + (light energy) ----> C₆H₁₂O₆ + O₂

​

​Essential in Photosynthesis

​Plants use water, carbon dioxide, and sunlight to create their food (sugar) and it creates oxygen as a waste product.

Water facilitates the movement of materials that are required for cellular respiration to occur.

​Transport

​Critical Role in Cellular Respiration

Bodies of water help keep temperatures stable. Cooler in warmer months and warmer in cooler months.​

​

​Temperature Regulation

​

Multiple Choice

What is an important role of ice in aquatic habitats?

• Insulation

• Shade

• Plant growth

• Ice skating

Multiple Choice

What happens to the structure of H2O when it freezes?

• It becomes less structured

• It becomes more structured

• It does not change structure

Multiple Choice

What happens to the density of water when it freezes?

• It increases

• It decreases

Multiple Choice

Water is considered?

• The universal solvent

• A bad solvent

• The universal solute

• A bad solute

Multiple Choice

What is the term for a substance that dissolves another substance to create a solution?

• Solute

• Water

• Solvent

• Solution

Multiple Choice

What is the term for a substance that is dissolved to become a solution?

• Solute

• Solvent

• Salt

• Water

Multiple Choice

Approximately how much of the human body is composed of water?

• 50%

• 60%

• 70%

• 80%

The amount of energy required to change the temperature of 1 gram of a substance by 1 degree Celsius​. The unit of measurement is calories which is equal to g/C°

​gram/degree celsius

​Specific Heat

​

​Water has a high specific heat

​Because of this it take a lot of energy to change water's temperature.

540 calories of energy are required for water to vaporize.​ This is the amount of energy required for a molecule of water to escape and become steam

​

​Water also has a high heat of vaporization

​