1. 9/11/13 12th Day of School Learning Goal (7.E.1.1): I will be able to describe the properties of Earth’s atmosphere. Due Today: 1 st 3 PowerPoint slides Evening Assignment: Work on atmosphere properties slide of Powerpoint

2. Do Now In your composition notebook, copy and answer the following… What words would you use to describe the properties of Earth’s atmosphere? McDougall textbook, p. viii

3. Do Now Did you get it right? What words would you use to describe the properties of Earth’s atmosphere? Altitude Density Temperature Air Pressure

4. Defining key words Why are these properties important? Look up and write down the definition in your science notebook for the following terms: Altitude Density Temperature Air Pressure McDougall textbook, p. A11

5. Defining key words What are the properties? Altitude: distance above sea level Density: the amount of mass in a given volume of a substance Temperature: how hot or cold an object is Air pressure: the force of molecules pushing on an area McDougall textbook, p. A11

6. The Composition and Properties of the Atmosphere make life on Earth possible. 1. Living things use gases in the air: oxygen, nitrogen, argon, carbon dioxide, & water vapor 2. The atmosphere keeps Earth warm. Transports energy to different regions of the planet (radiation, conduction & convection). 3. The atmosphere protects & supports life. 4.Supplies materials that your body uses. 5.The atmosphere is held in place by gravity.

7. Properties of Earth’s Atmosphere Altitude and Density Air becomes thinner as altitude increases. There is less oxygen. The thickness or thinness of air is measured by density. The atmosphere’s density decreases as you travel upward. The air on a mountain is less dense than the air at sea level. It contains less mass. Most of the mass of the atmosphere is close to Earth’s surface. McDougall textbook, p. A10

8. Properties of Earth’s Atmosphere Temperature Changes with altitude Temperature is warmer at sea level but decreases with altitude in the mountains. Measured with a thermometer. http://eo.ucar.edu/webweather/basic5.html

9. Air Pressure http://eo.ucar.edu/webweather/basic5.html Air molecules move in all directions, air pressure pushes in all directions. Air pressure decreases with altitude. The air molecules in air at sea level are denser than air molecules in air over a mountain. Air pressure is higher in dense air than in thin air. Areas of high pressure move to areas of low pressure. Measured with a barometer.

10. Major Assessment Assignment: Earth’s Atmosphere Powerpoint You will make a Powerpoint presentation about Earth’s atmosphere. You may use information and pictures from class, the textbook, other books, and the Internet but you MUST cite your sources (ex. title, page, web address, etc). Include text in your own words explaining any images you use. Your Powerpoint should have the following slides. Final Powerpoint is due Friday 9/13/13. Title slide with title, your name, period, date Slide defining atmosphere Slide(s) about the composition of Earth’s atmosphere Slide(s) about the properties of Earth’s atmosphere Slide(s) about the structure of Earth’s atmosphere

11. Evening Assignment Work on Title, atmosphere definition, Earth’s atmosphere’s composition and properties slides.