AtmosphereQuarter 3

2014 - 2015

Unit Topics of Study

Properties of Gases and the

Air we BreatheGas Laws and the Air we

BreatheWeatherAir Pollution

Properties of Gases and the Air we Breathe

• Main Ideas (in no order):

– Atmospheric Pressure– Volume– Temperature– Kinetic Molecular

Theory– Composition of Air

Comparing State of Gas to other known States of Matter

What observations can you make?

Properties of Gases

1. Gases have mass – find mass of empty balloon and filled balloon

2. It is easy to compress gases – squeezed gas reduces its volume; car air bags

3. Gases fill their containers completely – 4. Different gases can move through each other quite

rapidly – diffusion (body spray, body gas, etc)5. Gases exert pressure – ear drums “popping”, filled

balloon6. The pressure of a gas depends on its temperature -

↑ temp = ↑ pressure; ↓ temp = ↓ pressure

Gases in the Atmosphere

• What gases are in the atmosphere?

• How do the gases behave when there are changes in temperature? Volume? Pressure?

• How does radiation from sun affect those gases?

What gases are in the atmosphere?

“Exploring Properties of Gases”Lab Activity

Lab Activity Procedures for Each Station: Reread the procedure Review your prediction Perform the experiment Record your observations Restore the station to its original condition

When all stations completed, answer the questions

Lab Activity Review1. Which experiments are useful in

demonstrating that air is matter? Explain.2. Which experiments are useful in

demonstrating that air exerts pressure? Explain.

3. Explain any differences between your predictions and the actual outcomes of the experiments.

Review cont.

4. For any two of the stations at which you performed experiments, a. Describe your observations in detailb. Explain the role of air in the experimentc. Draw particle models showing the interactions between the gas particles in air and the other particles of matter in the experiment

Review cont.

5. Describe an additional activity or experience you have had that demonstrates that a. Air is matterb. Air exerts pressure

6. Home activity (or café): put one end of a straw in a glass of water. Hold another straw outside the glass. Place the ends of both straws in your mouth and try to drink the water through the straw in the glass.

a. Describe what happensb. Based on your observations, what makes it

possible to drink liquid through a straw?

The Nature of Gases

• Book pg 419 bolded