Science 8 – Unit 1 Water Systems Chapter 1

Chapter 1 – 1.1 Distribution of Water Key Points: Earth’s total water supply: 100% Earths supply of fresh water: 3% (does not contain salt) 2/3 of fresh water is frozen in large masses of ice (North and South pole and glacier) Earth’s Available fresh water: 1%

The Water Cycle Key Terms: Lithosphere, Atmosphere and Hydrosphere. All 3 are linked in the water cycle. The TWO main processes are: Evaporation and Condensation Evaporation is the change in state from a ___ to a ____. What do we need? Condensation is the change in state from a ____ to a ____. What do we need?

The Water Cycle What is it? It’s the recycling of water between the Earth and the atmosphere. Evaporation and Condensation are the main processes. Continuous Cycle, never ending.

Stages 1. Water is evaporated from the oceans, lakes and goes into the atmosphere as a gas. 2. This gas will stay in the atmosphere until it cools. 3. As it cool’s, its condenses to form clouds. (turns back to a liquid). 4. Precipitation back to Earth from clouds.

http://www.neok12.com/diagram/Water-Cycle-01.htm Aliant Learning Center – The Water Cycle

NEW Perspective on the Water Cycle http://www.neok12.com/php/watch.php?v=zX73676f0d5a4056514d7606&t=Water-Cycle Quiz on the Water Cycle http://teacher.scholastic.com/activities/studyjams/water_cycle/

Chapter 1: 1.2 Comparing Ocean and Fresh Water Salt Water differs from fresh water in THREE main ways: - Salinity - Density - Freezing Point

Salinity The amount of salt in a certain volume of water. 200 times as salt vs. freshwater The amount of salt in the ocean varies depending on where you are…

Salinity Location Salinity (High or Low) Why? Next to the Equator Next to the N and S poles Near the Continents

Salinity Question! Where does salt come from? Many sources: Water flowing over ground picking up materials from rocks, called dissolved solids. Volcanoes (above ground and undersea) Release sulphur, fluorine, chlorine and hydrogen.

Salinity Sodium Chloride is the most common material deposited in the ocean, also know as: S A L T 85% of all dissolved solids in the ocean is salt! http://www.youtube.com/watch?v=jNc8qmCYRGs&feature=related http://www.youtube.com/watch?v=iSJggIWlH9w

Density What is it? The amount of mass of a substance in a certain unit volume. Vs. Density Example: http://www.metacafe.com/watch/828833/the_great_soda_density_experiment/

Density Salt water has more SALT then fresh water, thus, more DENSITY.

Density Density and Salinity Demo http://teachertube.com/viewVideo.php?video_id=16140&title=Salinity_Density_Demonstration-

Freezing Points Salt Water vs. Fresh Water Freezing point is the point at which a substance freezes. Ocean water and fresh water have different freezing points due to the presence of SALT. As the salt content , the freezing point will .

Freezing Points Factor Ocean Water Fresh Water Freezing Point

Cool Science The Dead Sea http://www.youtube.com/watch?v=2A1XvaHGc-k