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Bell Ringer. Describe water without using the word wet. Brain Pop-http://www.brainpop.com/science/earthsystem/water/. Structure of Water. Water is made up of atoms Atoms attach together, or bond to form molecules. 2 Hydrogen atoms bond to 1 Oxygen atom form a water molecule ( H 2 0). - PowerPoint PPT Presentation
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Describe water without using the word wet.
Brain Pop-http://www.brainpop.com/science/earthsystem/water/
Bell Ringer
Water is made up of atoms
Atoms attach together, or bond to form molecules.
2 Hydrogen atoms bond to 1 Oxygen atom form a water molecule ( H20)
Structure of Water
Each end of a molecule has a slight electric charge
Oxygen = slight negative charge
Hydrogen =slight positive charge
Molecule that has electrically charged areas is a polar molecule
Structure of Water
Structure of Water The positive Hydrogen ends of the water
molecule attract the negative Oxygen ends of nearby water molecules.
The end result, the water molecules tend to stick together because of the electric force; similar to an magnetic force
Capillary Action Surface Tension Universal Solvent Specific Heat
4 Key Properties of Water
Combined force of attraction among water molecules and the molecules of surrounding materials
Example: drinking from a straw {pg 48} (you will see the liquid rise higher in the straw than on the outside of the straw) OR paper towel soaking up water
Water molecules are attracted to the straw, they pull other water molecules up with them
Capillary Action
the action or property of like molecules sticking together, having an attractive force
Water molecules are attracted to other water molecules
Cohesion
the tendency of water to stick to other substances
Water can also be attracted to other materials.
Adhesion
The tightness across the surface of water that is caused by the polar molecules pulling on one another.
The tightness of the water keeps the bug from sinking
The pulling forces the surface of the water into a curved shape
Surface Tension Surface tension
causes raindrops to form round beads when they hit a car windshield
Solution is a mixture that forms when one substance dissolves another
Solvent – the substance that does the dissolving.
Many substances dissolve in water because water is polar. (like the powdered Kool-Aid)
Water is a universal solvent because it dissolves almost everything
Universal Solvent
Is the amount of heat needed to increase the temperature of a certain mass of substance by 1 degree C.
Water requires a lot of heat to increase its temperature
Water’s high specific heat is due to the strong attraction among water molecules
Specific Heat
Water is the only substance on Earth that commonly exists in all 3 states of matter◦ Solid- ice cube◦ Liquid- water in a lake◦ Gas- water vapor (humidity)
Changing State
the process by which molecules at the surface
of a liquid absorb enough energy to change into a gaseous state
Water boils at 100o C and a change of state occurs
Molecules get enough energy to escape the liquid and become invisible water vapor (gas)
Changing State- Evaporation
As water cools down, it releases some of its energy to the surroundings
Molecules slow down and temperature decreases
Condensation- process in which a gas changes to a liquid
The sweat you see on the outside of a glass
Changing State-Condensation
Liquid water freezes at 0o C
Molecules lose
energy and move more slowly
An icicle forming from water dripping off a roof
Changing State- Freezing
As the temperature reaches above 0o C the solid ice melts and becomes a liquid.
Changing State-Melting
At the end of your notes write an eight sentence summary paragraph about your notes and turn into basket
Summary