1. Notes Science Essential Question(s) 1) What is the chemical composition of our atmosphere? 2) What evidence demonstrates that our atmosphere is a mixture and not a compund? Tennessee SPI Objective: Describe the chemical makeup of the atmosphere. Check for Understanding Explain how the chemical makeup of the atmosphere illustrates a mixture of gases. SPI 0807.9.5 Atmospheric Composition Instructions for Students 1) Make sure you view this presentation in slideshow mode. 2) You can find instructions about how to do this by doing a Google search or by searching YouTube. 3) After you have it in slideshow mode, press the right-arrow keyboard button to advance through the presentation. 4) If you need help, please communicate with your teacher.

2. SPI 0807.9.5 Atmospheric Composition Notes Science  An atmosphere is the mass of gases that surrounds a planet. and is held in place by gravity.  Planetary atmospheres are common in our solar system (Even the Moon has a very thin atmosphere.) Jupiter Earth What is an Atmosphere? Mars Saturn The Moon

3. Earth's Current Atmosphere …(approx) 78% nitrogen …(approx) 21% oxygen …(approx) 1% other gases (Argon, etc) (argon, water vapor, carbon dioxide, etc) SPI 0807.9.5 Atmospheric Composition Notes Science Earth's Atmosphere Earth’s atmosphere is a mixture of various gases Nitrogen 7 N 14.0 Oxygen 8 O 16.0 Argon 18 Ar 39.9 Remember! Our atmosphere is a MIXTURE & not a compound

4. Earth's Current Atmosphere …displayed with pie charts/circle graphs …(approx) 78% nitrogen …(approx) 21% oxygen …(approx) 1% other gases (Argon etc.) SPI 0807.9.5 Atmospheric Composition Notes Science Nitrogen 7 N 14.0 Oxygen 8 O 16.0 Argon 18 Ar 39.9

5. Earth's Current Atmosphere …approx) 1% other gases (Argon etc.) SPI 0807.9.5 Atmospheric Composition Notes Science Argon (Ar) Neon (Ne) Carbon Dioxide (CO 2 ) Helium (He) Methane (CH 4 ) Water Vapor (H 2 O) …and any other odor, pleasant or unpleasant, that you have ever smelled. What are the “other” gases? Note: They are called Trace Gases

6. Where did Earth's atmosphere come from?  from comets and planetismals  Venting from volcanoes  oxygen from plants (View Holt Online Ch15: Sect 3 VC) Notes SPI 0807.9.5 Atmospheric Composition Science

7. Where did Earth's atmosphere come from?  from comets and planetismals (water from space) Notes SPI 0807.9.5 Atmospheric Composition Science What are comets? Comets are giant "dirty snowballs" in space. They consist of frozen water, stellar dust, and rocky debris.

8. Where did Earth's atmosphere come from?  Venting from volcanoes 3 most common gases from volcanoes (1) Water Vapor, (2) Carbon Dioxide, and (3) Sulfur Dioxide Notes SPI 0807.9.5 Atmospheric Composition Science

9. Where did Earth's atmosphere come from?  oxygen from plants-photosynthesis (plants absorb carbon dioxide and release oxygen) Notes SPI 0807.9.5 Atmospheric Composition Science

10. Earth's Changing Atmosphere Millions of year’s ago, Earth’s atmosphere was mostly carbon dioxide, water vapor, and ammonia. What changed it? Plants converted the carbon dioxide to oxygen, and this oxygen broke down the ammonia into nitrogen.

11. Review Science SPI 0807.9.5 Atmospheric Composition Section number two in the circle graph above BEST represents the percentage of…? A) Carbon B) Oxygen C) Argon D) Nitrogen 1 3 2 Oxygen

12. In diagram 01 below, which gas is represented in the Portion labeled 1 on the pie chart? A) Argon B) Nitrogen C) Hydrogen D) Oxygen Diagram 01 Diagram 02 Nitrogen

13. Questions Science SPI 0807.9.5 Atmospheric Composition

14. Questions Science SPI 0807.9.5 Atmospheric Composition

15. Questions Science SPI 0807.9.5 Atmospheric Composition Argon Neon Carbon Dioxide Helium Methane Water Vapor Argon and various trace gases make up about 1% of Earth’s atmosphere.