A while ago I posted about an experiment that we had done using skittles, well we used that experiment to carry out another one; a skittles density tower. Although you wont be able to taste the rainbow at the end of it, you will certainly be able to see it.

Make sure that you are following our science board over on Pinterest for more ideas and don’t forget to pin the Pin at the bottom.

You will need:

• Skittles
• Pipettes
• Clear glass
• 5 cups
• Hot water
• Tbsp

Add 2 tbsps of hot boiling water into each cup (not the glass).

EC carefully adding the boiling water.

You need to have separate colours for this, so don’t add more than one colour skittle to each cup. The number of skittles that you need is very important. The first time we did this, it was a complete failure; and that was because we hadn’t used the right amount of skittles.

This was taken from the first time we tried, you need to double the amount of skittles.

The reason that this is so important is that you are trying to change the density of the liquid by having different amounts of sugar in each solution. The more sugar in it, the denser the liquid will be.

2 red

4 orange

6 yellow

8 green

10 purple

It is also important to keep a note of which cup contains which colour, they can look fairly similar once they have all dissolved and if you put the wrong colour in the wrong order it will ruin the density tower (which is also something that we also managed to do).

If the skittles don’t full dissolve, then put it in a microwave for 30 seconds to help it on its way. Let the water completely cool before moving on.  They have to completely dissolve or the density of the liquids will be the same.  When I did it by myself just to make sure it would work, I didn’t completely dissolve the purple skittles and so when I put the green on top it sank through the purple one (which was pretty cool, but wasn’t what I wanted to happen).

The final part is slightly tricky so patience is required.

Use the pipette to suck up your first colour (which should be purple) and fill up the bottom of your glass.

With all your other colours you have to be very careful when adding them on top of previous layer. The best way we found was to put the pipette to the side of the glass and slowly squeeze it in. It was actually really neat to watch how the colour would sink and then pop back up to the top again.

You can see the green layer beginning for form.

If you look carefully, you can see some of the green layer sinking down before it pops up again.

To create the rainbow effect you will need to put the colours in in this order; purple, green, yellow, orange and red.

I put the red in before the orange. Whoops!

EC and YC loved making their skittles density tower, it was a great experiment to use to start looking at the concept of density, and how liquids all have different densities to them. We are planning on doing this activity again, but this time using different liquids. Keep checking out the blog to see how you can do it too.

EC was really concentrating to make sure he didn’t add layers too quickly.

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