STEM: science with Beavers

I’m a ex-chemist so science is very near to my heart. I joined the STEM ambassador scheme through work and got my DBS check completed this summer.

I was also a Brownie, Guide and Young Leader in my school days.

Large boy joined Beavers about 18 months ago and is coming to the end of his time there. They’re working towards a science badge this term.

So the leaders asked us to help out. Himself did a session on filtration for water awareness in the spring so it’s my turn in a couple of days.

This is why I’m spending my Saturday afternoon preparing some activity sheets and practical sessions. The first evening we’ll cover felt tip chromatography and the pH of liquids.

Felt tip chromatography

There are loads of resources for this on the internet. I’ve picked my favourite bits for a nice easy experiment.

Himself has obtained a pack of proper filter paper, but coffee filters will work just as well apparently. I’ve tried a couple of ways to cut and get the water absorbed.

First a circle with a dangly bit and water in a little pot (I used an old tommy tippee milk powder tub):

Beautiful results but it’s really slow because there’s less contact between the water and filter paper.

The best option seems to be a flat edge cut off the filter paper in my fab Ikea beaker-like measuring jug.

You can clearly see that brown is made of blue, pink and orange. Purple is pink and blue (surprise!). Black is a bit of everything.

pH of liquids

Again, I’m benefiting from himself’s access to supplies and we’ve got some real pH paper to play with.

So I’ve chosen some easy to obtain liquids that are both acids and bases and prepared a little introduction to what that means.

I’m planning to split the children into five groups and ask each group to decide whether each liquid is an acid or base.

So I’ve got a box of stuff and I know what I’m doing, probably. But who knows what questions a bunch of 6 and 7 year olds will have. Fingers crossed!