1. Chapter 1 THE AIR AROUND US
The invisible, odorless, and tasteless mixture of gases that surrounds Earth.
NITOGEN:
A colorless, odorless, tasteless gas that makes up about four fifths of the air.
OXYGEN:
A colorless, odorless, tasteless gas that makes up about one fifth of the air.
CARBON DIOXIDE:
A colorless, odorless gas.
WATER VAPOR:
Water that is in the form of a gas.

2. ATMOSPHERE: TROPOSPHERE: WEATHER: GREENHOUSE EFFECT: WIND:
The blanket of air that surrounds Earth, reaching to about 700km above the surface.
TROPOSPHERE:
The layer of the atmosphere closest to the surface of the Earth.
WEATHER:
The condition of the atmosphere at a certain place and time.
GREENHOUSE EFFECT:
The process by which heat from the Sun builds up near Earth’s surface and its trapped by the atmosphere.
WIND:
The movement of air over Earth’s surface.