1. Science 8 – Unit 1 Water Systems
Chapter 1

2. 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%

4. 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?

5. 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.

6. 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.

7.
Aliant Learning Center – The Water Cycle

8. NEW Perspective on the Water Cycle
Quiz on the Water Cycle

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

10. 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…

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

12. 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.

13. 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!

14. Density
What is it?
The amount of mass of a substance in a certain unit volume.
Vs.
Density Example:

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

16. Density
Density and Salinity Demo

17. 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 .

18. Freezing Points
Factor
Ocean Water
Fresh Water
Freezing Point

19. Cool Science
The Dead Sea