Water Cycle - Atmosphere (5)

  • Discovering that some components of air can be depleted. 
  • Experimenting with air pollution. 
  • atmosphere
  • carbon
  • oxygen
  • pollution
  • beaker or glass jar
  • candle
  • matches
  • tray
  • water
  • leaves
  • clay (to hold candle)

Students create pollution.



Humans can alter the atmosphere by their activities on the surface of the Earth.  There are six major pollutants that are commonly recognized including:  sulfur oxides, particulate matter, carbon monoxide, nitrogen oxides, hydrocarbons, and photochemical oxidants.  The problems that they cause will be discussed during the Post Lab.  It is staggering to imagine that over 200,000,000 tons of pollutants are emitted into the air annually just by the people of the United States.

This is just a simple way to focus students attention that we put substances into the atmosphere.  Much of it is cleaned by rain or moved by wind.  Scientists do not agree on what all these pollutants are doing to our atmosphere.  Some say we are totally destroying our atmosphere real soon, others think nothing will happen.  The studies are very difficult to decipher, and it is even harder for non-scientists to come up with an answer.  The answer probably lies somewhere between the two extremes.  Remember your students may one day vote on issues like this, that need a careful understanding of the problem.

  1. Air has several components and this lab will illustrate that air can be chemically depleted of some of its gases.  Oxygen is needed for fire to burn and Experiment 1 shows students that the candle will burn as long as there is oxygen present, but will go out when depleted of oxygen.  
  2. Make sure you go over the dangers of matches.  You may want to divide the class so you watch them performing the experiment at each table.
  3. The second experiment points out that you can add components to air.  When you burn a match, the fire burns the match itself into particulate matter (soot).
  4. In the third experiment, the burning of the leaves is causing carbon to be placed in the atmosphere.  Notice there will be water vapor that is released which is not harmful.

  [Back to Water Cycle Grid]  [Back to Atmosphere (5)]