Living In A Hothouse

TOPIC: ATMOSPHERE
LEVEL: Advanced

"Living In A Hothouse"

CONCEPT:: Environmental conditions, temperature, density, and pressure, are continually changing.
STUDENT OBJECTIVE:: Students will construct a working model of the "greenhouse" to simulate the warming of the Earth and observe the effects.
OVERVIEW:: Heat is absorbed by the Earth and everything on it. This includes living and non-living things. After the Earth gets warm, dome of the heat goes back into the atmosphere. This is what scientists call the greenhouse effect. The gases act as a sort of "greenhouse glass". The gases let energy from he sun in, but they reflect the energy, as in heat, that the Earth re-radiates back toward the Earth. These gases hold heat in. The most abundant gas that is held in is carbon dioxide. This gas is the gas we exhale, cars and trucks burn gasoline which also creates carbon dioxide.
TEACHER TEXT:

PREPARATION TIME: 15 minutes

LESSON TIME: 60 minutes

TEACHER PREP:

WORDS TO KNOW:

MATERIALS NEEDED:

STEPS TO FOLLOW:: 1. Build a partition in the middle of the aquarium out of cardboard or plywood. Its edges have to fit pretty tight to the sides of the aquarium.; 2. Make the partition airtight by using a lot of tape.; 3. Place a thermometer in each compartment so that you can read them from outside. Shade them with a sheet of newspaper for a while.; 4. Now fill one chamber with CO2. Mix baking soda and vinegar in the bowl and place it in one chamber. You'll know the chamber is full when you strike a match that goes out as you slowly lower it into the chamber.; 5. Shine a bright light at each chamber from equal distances. Wait about 10 minutes, and then read the thermometers. Attach the lights to the aquarium.

WHY?: CO2 is heavier that air, so CO2 will just sit in the container for a long time if not disturbed. After about 10 minutes, the thermometer on the CO2 side will be a few degrees warmer than the one on the plain side. This is the greenhouse at work.

ASSESSMENT: Can the student communicate what they observed?: 4......Student will be able to communicate that CO2 is heavier than air, therefore will sink in the atmosphere. Some of the heat is re-radiated back into the atmosphere as a natural process. CO2 gets trapped in the atmosphere and does not re-radiate into the upper atmosphere creating a "blanket" around the Earth. This "blanket traps" the CO2 creating the greenhouse effect.; 3......Student will be able to communicate that warm air does not rise and gets trapped toward the Earth. This trapped air becomes warm and a greenhouse is created.; 2......Student will be able to communicate that the Earth becomes a greenhouse keeping the atmosphere too warm for Earth.; 1......Student will be able to communicate that the Earth is getting too warm.

Last modified: Thu Jun 12 17:47:02 PDT 1997