Save a balloon with water

Balloon in a candle flameWhat connects cooling computer chips, melting car engines, and a balloon that will not pop? This week’s science video sees Robert Krampf explaining the principles behind heat sinks, car radiators, water cooling, and how to hold a balloon above a burning candle without it ever popping.

Krampf points out that, “Because we’re using fire, always be sure you keep safety in mind, and be sure you’ve got an adult around, so that you’ll have somebody to blame if something goes wrong!”

So, what is it about water that makes it absorb the heat from the candle flame so fast and so protect the rubber of the balloon from melting or burning? Water has the second highest specific heat capacity of any known chemical compound, after ammonia. This is due to the extensive but transient network of temporary hydrogen bonds that form between the oxygen atom at the centre of each water molecule and a hydrogen atom from a neighbouring water molecule. This fluxional network of loose bonds allows liquid water to rapidly absorb heat and also allows the heat to quickly be dispersed through the bulk liquid.

WARNING: Please don’t attempt this experiment with anything but water in the balloon. Water is about the only fluid that is safe to use but more to the point, it won’t work properly with any other fluid.

2 thoughts on “Save a balloon with water”

  1. Thanks for your kind words anonymous. If these videos are something that you and other Sciencebase visitors would like to see more of, I’d be quite happy to resurrect the site’s weekly science video spot…

    Just leave a comment with a yeah or nay…

  2. I homeschool my daughter who will be in 5th grade during the 2007-2008 school year. The “tweeners” can be a hard generation to reach at times and most everything that catches their attention for any length of time does so because it was media centered, informative, fun, and unique. I set out to surf the satellites in search of dvd/video products available for purchase online for her to watch as part of our core curriculum for the coming school year. Your blog came up in my search and you left a reference to this video in the particular blog entry that appeared in Google’s search results. I watched the video and loved it! It’s exactly what I remember watching at my daughter’s age in class during various lesson plans. There was always a brief video clip to enforce the curriculum. After viewing the video, I tagged the site ( and after looking around, I’ve added it to my favorites. I will definitely be sharing it with my daughter and most certainly other homeschooling families. Thank you so much for your contribution to the education of science online. It’s greatly appreciated and will definitely make one homeschooling tween a happy student this year.

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