1. Journal #18 What is the atmosphere? What do you think it is made of? What do you think makes up air?

3. The Atmosphere The layer of gases that surrounds Earth is called the atmosphere. The atmosphere is made up of a mixture of chemical elements and compounds that is known as air. Such as Oxygen, carbon dioxide, nitrogen etc. The atmosphere protects Earth’s surface from the sun’s radiation and helps regulate the temperature of Earth’s surface.

4. Composition of the Atmosphere The most abundant elements in the air are the gases: nitrogen, oxygen and argon. The composition of dry air is nearly the same everywhere on Earth’s surface. The two most abundant compounds in air are the gases carbon dioxide and water vapor. The air in the atmosphere also carries tiny solid particles such as dust and pollen.

5. Nitrogen in the Atmosphere Nitrogen makes up 78% of Earth’s atmosphere. Nitrogen is maintained in the atmosphere through the nitrogen cycle: What is nitrogen fixation?

6. Oxygen in the atmosphere Oxygen makes up about 21% of the Earth’s atmosphere Animals, bacteria, plants, forest fires, burning of fossil fuels and weathering of rocks removes oxygen from the air. Land and ocean plants produce large amounts of oxygen through photosynthesis.

7. Oxygen in the Atmosphere

8. Water Vapor in the Atmosphere As water evaporates it enters air as invisible gas called water vapor. Plants and water give off water As water vapor enters the air, it is removed through condensation and precipitation. The amount of water vapor in the atmosphere changes depending on: Time of day Location Season

10. Ozone in the Atmosphere Although it is small, the ozone (made up of oxygen) is important in the atmosphere. The ozone is the upper part of the atmosphere that forms the ozone layer. This layer absorbs ultraviolet radiation form the sun. Common waste products from machines (refrigerators, air conditioners, exhausts) break down the ozone? What does this matter?

12. Particles in the Atmosphere In addition to gases, the atmosphere contains tiny solid particles. These can come from volcanic dust, ash from fires, salt from seasprays or minerals from soil. Pollen from plants and particles from meteors that have vaporized are also particles.

14. Let’s Review 1. What is the atmosphere? 2. How does the atmosphere help and protect us? 3. What elements are in the air? 4. What compounds are in the air? 5. Does the air carry solid particles?

15. Review: How much of the air is made up of nitrogen? How does nitrogen move through the atmosphere? How much percent of the atmosphere is made up of oxygen?

16. Review: What is called when plants create oxygen from carbon dioxide? When water evaporates it become invisible air called __? What 3 things can change the amount of water vapor in the air? What is the ozone and why is it important?