Ch. 2 Sec. 1

Energy in the Atmosphere

electromagnetic waves• form of energy that can travel thru.

vacuum of space

radiation• direct transfer of energy by

electromagnetic waves

visible lightMade of colors in

the rainbow:

RedOrangeYellowYellowGreenBlue

Indigo Violet

ultraviolet radiation• wavelengths - shorter than visible

light

• causes:

1. skin cancer

2. eye damage

3. sunburns

infrared radiation• wavelengths- longer than red light

• not visible

• felt as heat

What happens to sunlight in the atmosphere?

•reflection of light in all directions

scattering

greenhouse effect •process by which gases hold heat in air

Greenhouses are structures designed to retain heat.

Discover Activity -Does a Plastic Bag Trap Heat?

1. Record the initial temperatures on two thermometers. (You should get the same readings.)

2. Place one of the thermometers in a plastic bag. Put a small piece of paper in the bag so that it shades the bulb of the thermometer. Seal the bag.

3. Place both thermometers on a sunny window ledge or near a light bulb. Cover the bulb of the second thermometer with a small piece of paper. Predict what you think will happen.

4. Wait five minutes. Then record the temperatures on the two thermometers.

• Think It Over• Measuring Were the two temperatures the same? How

could you explain any difference?