Willie Hoskins - Williams School  



Topics in Environmental Science

Willie Hoskins                 Williams School  
                               2710 S. Dearborn  
                               CHICAGO IL 60616
                               (773) 534-9226

Objective(s):

To model the atmosphere of the earth.  To build a model to simulate the 
greenhouse effect.  To use diagrams and models to generate data. To analyze and 
interpret data, especially the results of introducing pollutants into nature.  
To form scientific hypotheses of how long-term exposure to pollutants will 
affect the future of the earth.

Materials Needed: 

candles, matches, saucers, dirt, rocks, gravel, small plants, water, lamp, 
thermometer 

Strategy: 

The instructor strikes the match and lights the candle.  Each student is asked 
what he or she observed.  The instructor will hold the bottom of a saucer over 
the flame.  Then blow out the match and examine the underside of the saucer.  
The same procedure will be repeated with burning paper.  Discuss what was 
observed and conclude that when the yellow part of the flame came in contact 
with the cool dish, a black substance as well as moisture was deposited 
moisture also was present.  Explain to the students that anything can be 
called a fuel, and that most fuel contains carbon, hydrogen, or both.  When a 
carbon containing fuel burns incompletely, it usually glows with a yellow 
color and deposits black carbon as was seen on the saucer.  When the flame 
cools more slowly, the carbon in the fuel joins with oxygen from the air and 
forms carbon dioxide (CO2), a colorless gas.  The moisture formed on the 
saucers, because every flame gives off water vapor.  This is because the fuel 
contains hydrogen which reacts with oxygen in the air to form water vapor. 

Draw and illustrate all levels of the Earth's atmosphere.  Take two clear 
plastic containers and fill with two centimeters of gravel and one layer of 
rocks.  Add one and a half inches of soil.  Plant plants in the dirt,  put a 
little water on each new planting, add one more inch of soil, and water until 
soil is soaked.  Place a thermometer in the soil and be sure the bulb is 
submerged in the soil and the end is resting on the wall of the container with 
the number clearly visible through wall or top of container.  Cover one of the 
containers with plastic or plastic wrap.  Check the thermometer in both 
containers after 40 minutes.  Discuss and record data and conclude that the 
temperature increased in the covered container. 

Performance Assessment:

Students should observe the changes in the atmosphere and the soil temperature 
inside the container at different times compared with the atmosphere and 
temperature of the room.  
They should also compare the model greenhouse and the illustration of Nature's 
Greenhouse.  What happens at different temperatures?  What happens during 
photosynthesis?

Conclusions:

Incomplete combustion of fuels can lead to the production of soot.  Heat 
trapped by the cover of an artificial environment increases the temperature of 
that environment just as thought it happens in the greenhouse effect on 
Earth.

References:

Navarra, J. G. and Zafforoni, J., Today's Basic Science, Harper and Row, New 
York (1971), pp. 38-47.

Understanding the Greenhouse Effect, Ward's Natural Science, P.O. Box 92912, 
Rochester, NY 14692 (1989).