- Slides: 5
Chapter 15. 1 The air around you • Key Concepts: What is the composition of the earth’s atmosphere? How is the atmosphere important to living things? • Key terms: weather, atmosphere, ozone, water vapor
Weather • Weather is the condition of Earth’s atmosphere at a particular time and place. • The atmosphere is the envelope of gases that surrounds the planet.
Condition of the atmosphere • Earth’s atmosphere is made up of nitrogen, carbon dioxide, water vapor, and many other gases, as well as particles of liquids and solids • Nitrogen – most abundant gas in the atmosphere (about 75%) • Oxygen – 2 nd most abundant, makes up less than 25% • Involved in a lot of processes (eg burning/combustion) • Ozone – 3 oxygen atoms together.
Atmosphere continued • Carbon dioxide – 1 carbon to 2 oxygen. • Plants need it to produce food • Fuel burning releases it • Other gases – oxygen and nitrogen make up 99% of dry air • Water vapor – water in its gas form • Particles – pure air contains only gas. “Pure” air only exists in laboratories.
Importance of the atmosphere • Earth’s atmosphere makes conditions on Earth suitable for living things. • Contains oxygen and other gases that living things need to survive. • Warmth and liquid water • Atmosphere protects Earth’s surface from being hit by asteroids.