In the same groups, get the students to use the straw to blow bubbles approximately 5 cm in diameter. Use a stopwatch to time how long it takes for the bubble to burst and record this in the notebook. Also get the students to record anything they see happen to the bubble before it bursts. Do this at least 10 times and calculate the overall average time. Repeat this for bubbles approximately 10 cm in diameter (if they can make them).
Now see how the weather affects the life span of the bubbles. Repeat one of the experiments (5 cm or 10 cm) in a sunny spot, a shady spot and a windy spot (if nothing else, under the air conditioner).
Bring the students back together and compare and record all of the results.