Let's Find Out, with Captain Zoom and her human friends Amy and Mark, travel the galaxy answering Zoom's big questions.

Check out the RTÉ Player to watch the full episode HERE and all the series so far HERE!!

It's RTÉjr's science show and it's produced with support from Science Foundation Ireland.

Here, Zoom wonders why some liquids are runny and flow easily and some are thicker and harder to pour. She discovers that it's all about something called viscosity with the help of Conor and Alex.

They will measure the viscosity (it's a bit word!) of different liquids, by seeing how long it takes for marbles to fall through them! Which marble will win the race? Let's find out through this cool science experiment!

And you can download the full lesson plan here...

You will need:

  • Four thin glasses or test-tubes (all the same size)
  • Four marbles (all the same size)
  • A stopwatch or timer
  • Some water, oil (vegetable oil or similar), syrup (suck as maple syrup) and honey
  • Paper and pencil to record your results

What to do:

  1. Fill each container with each of the liquids, so one will contain water, one oil, one syrup and one honey.
  2. Drop a marble into the water and get someone to start the stopwatch or timer as you do.
  3. Record how long it takes for the marble to pass through the liquid and reach the bottom of the glass.
  4. Now do the same thing for the test-tube containing oil, then the one containing syrup and finally the one containing honey.
  5. Did you notice that the marble drops at different speeds in each liquid? Which one was the fastest and which one was the slowest?

The science bit

The marble passes at different speeds through different liquids and they have different thicknesses. We call this viscosity. The marble passed quickly through the water so the water was not very thick or viscous. The oil was a little more viscous than the water so the marble was a little slower falling through it.
The syrup was thicker, or more viscous still and the honey was the most viscous so the marble took the longest to pass through it.

Also in this episode...
Mark walks on custard!
And the whole crew go see one of nature’s most amazing liquids - lava!

AND there are lots more experiments with videos and full instructions - Just click HERE!