Guest post by Kate Roberts (“maths geek” and mum)


My child’s infants school were running a Science Week and asked for helpers via the newsletter. After a chat by phone, I dropped off some brief notes with some ideas for activities that I would enjoy doing with the kids.

One of the benefits of getting involved in this kind of initiative is that it pushes you to challenge yourself with things that you do with your own kids. I had a week head start to develop my ideas. I brainstormed a long list with the help of the Internet (including The School Gate SET website!) and set up prototypes for my children to play with.

The final decision was to do ‘chromatography flowers’. The basic activity is that a stripe or pattern is drawn in felt tip half way up a coffee filter paper. When the tip of the paper is dipped in water, the water is drawn upwards through the paper. When it reaches the felt-tips, the colour disolves into the water and is carried some way further up the paper. The colours are re-deposited, but will separate slightly. The colourful final paper is dried and mounted on a pipe cleaner as a ‘flower’. I adapted an idea from


Although the kids involved were aged 4-6, I was still keen to make sure that I was running a science activity – not just a crafty activity with hidden science. For the younger (Reception aged) children, I ran the activity in small groups in a free flowing Early Years environment. I had some prepared questions to guide them to think along scientific lines. I commented about the water flowing upwards,

“Does water normally go upwards? Hmmm….”

I also asked them what colours they could see on their paper – and if there were any colours on the paper that they hadn’t drawn on. Where might those extra colours have come from?

For the Year 1 children I put together a structured lesson plan (link here) that had quite a fast paced rate of little demos to get their minds ticking in the right direction. We started off whole class, then separated to do the activity, then came back to the carpet to discuss what they’d observed.


The only demo that did not come off was the capillary effect demonstration – if I did it again I might try to get hold of some real capillary tubes, not just plastic straws!

In terms of the making of the flower, some key learning point were:

  • Prefold the paper into thirds to give the kids a guide to where you want them to draw,
  • Have plenty of paper towels to rest the “flowers” on while they’re drying,
  • Let staff know in advance you’ll need water and water containers (as well as felt tip pens),
  • Warn the kids not to do their best art, since it will be dissolved in the water,
  • Get the children to write their names at the top of their flowers in pencil before they get wet.

There was also a bit of a bottleneck as I’d been a bit over-optimistic that the kids would be able to wind their own pipe cleaners onto their flowers.


I had great fun working with both year groups. The Year 1 children in particular really did seem to pause for thought around the ‘set piece’ demonstrations. I mixed up yellow and blue paint to make green, and at one point I had a queue of five volunteers trying to ‘unmix’ the yellow paint out of the green, until at the end they all seemed really on board with the idea that separating mixtures was much harder than mixing them. I’d expected to have to work harder to get them excited, but they were really very receptive.

I introduced myself to the kids as ‘Dr Roberts’. It was vaguely embarrassing to have my daughter’s TA getting her mouth around a different name for me – but it was totally worth it when little boys  confidently challenged me:

“You’re not a doctor; you’re not a scientist; you’re XX’s Mum!”

One kid told me, “You’re just pretending, to make the lesson more fun for us“!

I came away much more convinced of the value of the “not all scientists wear white coats” message!

Science Week Activity: Chromatography Flowers
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