An Introduction to Water

Foundation Science

Today’s Lesson: Water

Importance of Water

If there was no water, there would be no life

Why is water important?

1) The first life on earth came from water2) All organisms depend on water to survive

A human can live only 3 or 4 days without water!!!

How Much Water is There?

Water covers 71% of the earth’s surface

Where is water found?1) Oceans 96.5%2) Groundwater 1.7%3) Glaciers 1.7%4) Lakes about 0.09%5) Vapor, clouds, precipitation 0.001%

How Much FRESHWATER is There?

Freshwater is water without salt; the Chao Praya river is freshwater

Only 2.5% of the earth’s water is freshwater, the rest is saltwater from the oceans

99% of the earth’s freshwater is groundwater or ice (snow), 0.3% is in lakes and rivers, and the rest is in animals

THE WATER CYCLE

• Water in oceans, lakes rivers or on land evaporates into the air.

• It then turns into rain and falls back to the earth and the process begins again…….

WATER VAPOR

• Water vapor is water molecules in the air

Evaporation

Evaporation is when liquid water turns into water vapor

Condensation

• Water vapor turning into liquid water is called condensation

• Water vapor condenses when it hits a colder object

Precipitation• PRECIPITATION

is the condensed water in the air that falls to earth

• PRECIPITATION = RAIN

THE WATER CYCLE

QUESTIONS1. Draw a picture showing water evaporation,

condensation and precipitation.2. Is there water vapor all around you right now?3. When you have a cold drink, is it precipitation that forms

on the cup, or condensation?4. Explain in your own words why water forms on the

outside of a cold cup.5. Raindrops need to form on something in the air to make

precipitation. What does the water vapor condense onto??