Pajamas Science – Rainbow Jar

06 Apr

Most of the times I manage to do set up anything educational with my kids nowadays is happening either on holidays or weekends, and mostly in the mornings. When pajamas are still on and there’s no need to go anywhere fast.

Yesterday the day started slowly with lots of books and playing, then I remembered about a Density of Liquids Rainbow Jar experiment I wanted to do with girls. Found on Playdough to Plato

I couldn’t find some of the ingredients in UK (I think the blog is American), so I substituted them with what I could find. Some thing worked, some didn’t but at the end it turned out not so bad!

Here is what we used and how we started the experiment

I put out all of the supplies and scales and explained that we are going to do a little experiment and make a Rainbow Jar (I showed her the picture, so she was interested in the end result)

  1. A tall jar (I think ours was too big, choose taller and narrower one, so you don’t have to use too much materials.
  2. Honey
  3. Clarke’s Carob Fruit syrup (closest I could find to Corn Syrup)
  4. Fairy green washing up liquid
  5. Olive oil
  6. Water
  7. Absolute Vodka (closest I had to Rubbing alcohol)
  8. Food coloring
  9. A dropper


I gave Mya 2 jars with only a few marbles in one and full of marbles in the other and asked what she can tell me about them. She said that one had less marbles and other had more. We weighted them and came to conclusion that the one with more marbles was heavier.

I explained that everything is made from molecules – just like these marbles, but so tiny that you can’t see them. All our liquids that we are going to use are made of molecules too, and some of them have more molecules in them so they are heavier than the others, and the heaviest things will stay at the bottom.


We started with honey (no measures of how much of anything you should use – just enough to have a nice thick layer). Then we colored Carob syrup purple and poured that in – carefully, right in the middle. It was difficult for Mya not to pour it down the sides so I had to guide her hand (in pouring most of the liquids, as I didn’t want to spoil the  result of experiment and put her off the future ones). She wasn’t very happy with that. I don’t know why I didn’t think of using a funnel.. Duh!

Next – in went dishwasher liquid, followed by some water in colored blue. After water- we poured in some Olive oil and last went in Vodka colored in red. You’re not supposed to pour that one down the middle, but instead drop it down the sides with a dropper. Mya tried it first, but it was going everywhere, so I took this one over as well. This one didn’t go well – no matter how I tried – it went under the layer of oil and didn’t want to stay on top. My guess is – it wasn’t a good substitute for Rubbing alcohol, and was probably heavier than needed, or we weren’t careful enough pouring it in. Nonetheless – it turned out not so bad, and Mya has a basic understanding of molecules.

Be careful not to shake the jar – this will spoil the carefully arranged layers.

During the experiment Mya enjoyed mixing food coloring in and pouring liquids, Neva (2,3) enjoyed opening all the bottles, pouring marbles from one container into another, eating cheese and anything else I put on her plate for distraction and singing Rainbow song we made up. She wasn’t bothered by the rainbow jar. She wanted to drink Vodka…

I put the bottle back into the cupboard. I might need it for cleaning up courage….





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