Understand the composition and importance of air (including wind energy) and the sources, scarcity, and conservation of freshwater.
Preview · progress not saved — Chapter 1 is free
Hook on the necessity of oxygen.
Set goals for learning about air and water.
Explanation of the gases that make up air.
Air is a vital part of nature that surrounds the Earth. We cannot see it, but we can feel it when the leaves rustle or clothes sway on a line. The air is actually a mixture of different gases.
Visual representation of air composition.
A visual breakdown of the mixture of gases in Earth's atmosphere.
Explanation of wind and windmills.
Moving air is called wind. Sometimes it blows fast during a storm, and sometimes it blows gently as a breeze. Just like wind spins a paper firki (pinwheel), it can also rotate the large blades of a windmill.
Checkpoint summarizing air and wind.
Explanation of water distribution and scarcity.
Water covers about two-thirds of the Earth's surface. However, most of this water is found in oceans and seas. This water is saline (salty) and is not fit for domestic, agricultural, or industrial use.