Do diet drinks and full strength drinks float the same amount when in water? Do they both have the same density?

Let’s test this and see how density is related to how much sugar is inside some cans of soft drink.

  • Can of coke and diet cokeSoft drink density step 1a
  • Tub of water
  • Scales (optional)



1. Large volume of water is needed for this experiment. Conduct outside and have parental supervision.

2. Do not leave tub of water around near small children.

  • soft-drink-density-experiment-step1Place the Coke can in the water, tip to one side to remove air bubble in can bottom.
  • Soft drink density coke weightRecord the mass of the Coke Can (ours was 400g) on a set of scales.
  • soft-drink-density-step3Now add the diet coke can, again remove the air bubble on the underside of the can.
  • Soft drink density dcoke weightMeasure the mass of the Diest Coke can on a set of scales (ours measured 380g)
  • soft-drink-density-finalThe results!

Check out the ‘Wacky Science’ video of this experiment and ‘What’s Going On’ series link. They are currently ‘In Production’, so check back soon…..

Wacky Science Ep

What's Going On?



You guessed it, density is the science concept we are looking at here and if you have done our other experiments you can tell me that density is a measure of how much mass there is in a specific volume.

You also probably can say that since both cans have the same volume (375mL), then the one that is heavier should sink and the one that is lighter should float. YES correct.

The difference here is that the Coke can has LOTS of sugar in it while the Diet Coke has artifical sweetner in it. That means the Diest Coke has LESS mass compared to the heavier Coke.

If you would like

– more details,

– pictures of the second half of the experiment

– information on how to investigate this further

– links to everyday examples

– management hints & teaching pointers (5P Teacher develpoment program)

 ….. then why not subscribe to one of the following


(1) Crazy science Club

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(2) 5P Teacher Training course called ‘Looney Lab  Classroom Creations

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Or you can purchase the ‘Bright Sparkes Guide’ of this demonstration only ($2.50) which has:

    • HD pictures of experiment steps
    • Detailed explanation of science
    • Mini-challenge section (another experiment)
    • Making it a ‘Scientific Method’ experience
    • Graphing opportunities
    • REAL links and descriptions to everyday examples of concept.