Unit on Fireworks
by Gerald Wasserman and Thomas Witkowski
Objectives:
To stimulate critical thinking.
To demonstrate how science influences politics and art.
To explain the chemistry of fireworks.
Based on a 50-minute class period.
Day 1
Fire Writing
Materials:
Wood splints, matches, porous paper, 100 mL of saturated potassium nitrate (KNO3) solution, tape.
Procedure:
- Dip a splint into the solution and write a continuous message on the paper. Trace it three times. Allow the paper to dry.
- Tape the treated paper flush to the blackboard. Touch a glowing splint or lit match to the message. [It glows & sparkles.]
- Tape an untreated paper flush to the blackboard. Try to light it near the center with a glowing splint or lit match. [It may become charred but won’t light.]
Disposal:
- Board should clean up with wet cloth.
- Flush solution down the drain with excess water.
Observations:
- Ask students to describe what happened or didn’t happen. [Many students will confuse observations with "stories" (hypotheses). This may be a good time to introduce or reinforce the difference.]
Discussion:
- Have students offer explanations for their observations. [Students will most likely believe that some sort of fuel was placed on the paper that burned. At this time you may wish to explain that the paper was the fuel, and since it was present in both trials, a different explanation is necessary. In fact the potassium nitrate provided a source of oxygen, which was limited by taping the paper flush against the blackboard.]
- Ask students how they would test their explanations. [Answers will vary. Removing the untreated paper from the blackboard and then trying to light it would provide another useful observation.]
Applications:
- Weapons and construction. [Many explosions occur because of combustion in closed containers where free oxygen in not present.]
- Fireworks. [Can be used to show the influence of science on art. Different colors can be produced by mixing other salts in addition to the potassium nitrate with the fuel.]
Day 2
Video "Fireworks" from NOVA
- Students are to write 5 significant facts from this video. [Example: Altitude of fireworks correlates to size of the shell. 3-inch shell explodes at 300 feet. 6-inch shell explodes at 600 feet. 12-inch shell explodes at 1200 feet.]
- Homework assignment due on day 5, choose one of the following:
- One page article on the history of fireworks.
- Poem about the beauty of fireworks.
- One page report on how fireworks affect your emotions.
Day 3
Laboratory investigation on how different color flames can be produced by using different metallic salts. [Examples: potassium = purple, lithium = red, copper = blue. Lab report not available at this time. Investigation involves placing droplets of various salt solutions in the flame of a Bunsen burner.]
Day 4, part 1
How is the shape of fireworks determined?
Have students use Internet to research newspaper article from Philadelphia Inquirer, July 3, 2002.
Day 4, part 2
Completion of NOVA video [This portion deals with the artistry of fireworks.]
Day 5, part 1
First part of class period.
Written assessment:
- What was the political, artistic, and religious significance of where fireworks originated?
- Have students identify several metallic salts using a flame test.
- Have students explain how computers are used in fireworks displays. [Coordinating explosions with music or other cues.]
- Have students make a graph showing the relationship between shell size and the height of the burst.
Day 5, part 2
Review homework assignment from day 2.
Extra credit assignment.
- Have students develop a short fireworks display and coordinate it with a musical selection of their choice. Examples: rap, gospel, classical, old fashioned rock [Students may use drawings]