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Classroom and Laboratory Safety Signs

Author(s): Nancy Moreno, PhD, Barbara Tharp, MS, and Judith Dresden, MS.
Showing Results for: breathing rate Return to Presentation


You will need the following materials for this activity. 

  • 2 balloons (9-in., round)
  • Pair of scissors
  • Prepared small or medium-sized clear plastic bottle (soft drink, water, or detergent bottle)


This investigation works best with groups of two to four students. Each group may build a single Breathing Machine, or every student may build his/her own. At least one day before beginning this activity, ask each student or group of students to bring a small or medium-sized clear plastic bottle from home (half-liter water or soft drink bottle, or liquid dishwashing detergent bottle). 

NOTE: Liter-sized soft drink bottles are too large for this activity.

Cut off and discard the bottom third of each bottle, leaving about six inches (15 cm) remaining. If the cut edges are sharp or jagged, cover them with clear plastic packaging tape. 

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