Bigger and better bubbles

With a range of materials on offer, and the opportunity for ongoing exploration, learners will love this experiment into surface tension. 

This experiment should take 120 minutes. 

Equipment

• Eye protection may be used if there is concern about soap stinging the eyes, but is not essential.
• Length of thickish wire – 1 metre (or various sizes of wire hoops)
• Pliers
• fly-swat
• Filter funnels
• Yoghurt pots
• Plastic lemonade bottles
• Pipe cleaners
• Small syringes
• Glass droppers
• Measuring jug
• Bowls
• Scissors
• Stop clocks
• Rulers, 30 cm 
• 4 or 5 different brands of washing up liquid
• Kitchen soap
• Glycerine
• Sugar
• Salt
• Water

Health, safety and technical notes

Read our standard health and safety guidance here.

Wear eye protection if desired.

Wear lab coats, or aprons if desired. 

This is an open-ended problem-solving activity, so the guidance given here is necessarily incomplete.

Possible approaches

“Good experiment for a hot sunny day outside!” Lots of variables to consider.

Agreement must be reached on how to measure bubble size – in one school 7-8 year old students decided to catch the bubble on a hoop and hold it near a ruler.

You might also have a session on bubble blowing without recording.

For an article that describes the preparation and use of a bubble chamber, in which students can view a bubble from the inside out, see Chemistry for kids: “Invitation to Chemistry through a Large Soap Bubble Chamber” Sanae Sato, J.Chem.Educ., July 1988, Vol 65, p616.

Possible extension

Invent a bubble-making machine so there is no need to blow one bubble at a time using your ‘lung power’. 

Notes

• For younger students, the problem can be simplified by giving no choice of detergent, and no glycerine. For all but the oldest, the glycerine is best avoided, or there will be too many variables.
• A wet, soapy slippy floor is dangerous, so mop up any spills and watch where you put your feet.
• Do NOT put bubble mixture in your mouth.
• Do NOT blow bubbles into eyes.