Composition of the atmosphere Composition of the Atmosphere

Composition of the atmosphere

Composition of the Atmosphere ▪ Composition = what something is made of. ▪ “Air” is all around us and it behaves often like a liquid- it flows, moves, and causes things to happen (weather!) ▪ Air = mixture of dozens of types of gases.

▪ Air has MASS!! This means it can exert a FORCE (push) on you! ▪ The air that surrounds the planet is held in place by gravity and is called our atmosphere. ▪ Gravity becomes less and less as you move away from Earth. ▪ As a result, there are fewer and fewer molecules as you move away from the surface.

Air!!! ▪ The air around us is 78%: NITROGEN ▪ 21% of the air around us is: OXYGEN ▪ The remaining 1% is a mixture of all other gases: Carbon dioxide, helium, argon, neon, hydrogen…

Water Vapor ▪ Water is present in gas form in the air we breathe. We call this water vapor. ▪ The amount of water vapor in the air is called “humidity” and varies greatly with time and location. ▪ Water vapor is an important part of the water cycle and is a driving force in most types of weather.

POP QUIZ ▪ 1. ____ is a mixture of gases. ▪ 2. ____ is a blanket of gases that surrounds a planet. ▪ 3. 78% of our atmosphere on Earth is made of what gas? ▪ 4. 21% of our atmosphere on Earth is made of what gas? ▪ 5. Humidity refers to the amount of water _____ in the air.