Earth and Life Science SHS 2.2 Water The Medium of Life

Water The Medium of Life

The Hydrosphere

• The hydrosphere includes all of Earth’s water.

Saltwater

• Saltwater (oceans and seas) primarily have high salt content

Freshwater

• It has zero to very little salt content.

Global fresh water 2.5% fresh water vs 97% saltwater

Properties of Water

Density

○ Water is at maximum density at 3.98°C.

Heat Capacity

○ Water has a relatively high heat capacity, which

allows it to resist temperature changes.

The Origin of Water on Earth

• The prevailing hypothesis on the origin of water on Earth

suggests that water came from comets that collided with

Earth

key points

1. Hydrosphere is the water environment of Earth.

2. Saltwater has a significant amount of salt content

   dissolved within.

3. Freshwater has zero to minimal salt amounts

   dissolved within.

4. Only 2.5% of water on Earth is freshwater