Fun science experiments for kids at home: Let It Glow *

GIFTED | For a long time now, my daughter, Flora, has been a passionate fan of science.  She has a boundless curiosity, so anything we can find to develop and encourage that is amazing.  Among her favourite activities are the fabulous kids science subscription boxes from Letterbox Lab.  Tailored to the KS2 National Curriculum for STEM and STEAM, these fun science experiments are always eagerly awaited.  And none more so than our latest box, Let It Glow.*

Letterbox Lab

For those who don’t know, Letterbox Lab is a series of 12 linked science kits with full instructions and tools (you only need to add water for some of the experiments).  Online resources and videos accompany every box, plus some suggestions for further experiments and extension activities.  The Explore box (for age 6+) and the Investigate box (for age 8+) both support the UK primary school curricula, and one off boxes start at £11.00 including P&P.

Let It Glow

Let It Glow is the fifth in the Investigate box series.  This time we had whopping nine different fun science experiments, with a (hugely helpful) Messiness star rating at the beginning of each one.  Flora ADORED her previous box, Rocket Fuel, so she’s been bugging me constantly to get going on this one.  Once again, despite promising to go faster, this box has taken a long time to review.  I can only plead pressures of work, the darker evenings, and a jam-packed social life (Flora’s, not mine, sadly).  Anyway, here’s what was inside and this is how we got on.

• Secret Messages – secret message pen (UV torch), tube of sunblock, cotton bud and yellow UV paper
• Glow with the Flow – secret message pen (UV torch), tube of glow powder, tube of glow liquid, the safety goggles from Box 1, the test tube rack and three test tubes from Box 3, four black sheets and sticky tape to make up the dark box, and some water
• Photon Beam of Destruction – black balloons, clear balloon, fold back clip, and magnifying glass
• Ultra Colours – secret message pen (UV torch), tube of sunblock, cotton bud, ultraviolet beads, string, two small plastic bags
• Solar Photography – sun paper, pictures of Meg and Pico in silhouettes, the scissors from Box 1a plate, and some water
• Solar Powered – cress seeds, petri dish, kitchen roll, and some water
• A Warm Reaction – bottle of calcium chloride, safety gloves, the test tube rack, one test tube, safety goggles, measuring cylinder from Box 1, and some water
• The Fast and the Luminous – three glow sticks, the test tube rack, three test tubes, the dark box, a freezer, and some water
• Mini-Beast Safari – the magnifying glass and booklet
• A 24-page instruction booklet, a safety sheet, and a Glow It All badge.

Secret Messages

Did you ever write in lemon juice as a kid and then hold it over a heat source to reveal your secret code?  Same kind of idea here, but this time with invisible ink and ultraviolet light.  The magic bit: the torch gives off both violet light which we can see, and ultraviolet light which we can’t.  The ink can absorb UV light and give it back as a different kind of light that we can see, hence the glowing (hitherto invisible) writing.

Flora had to write a secret message on both white and yellow paper before shining her torch on her hidden designs.  On white paper, the ink showed up blue, and on yellow paper it showed up green, but was harder to see too as the whole of the yellow-dyed paper glowed.

Next she had to experiment with smearing sunblock on the paper with a cotton bud to see if that would block the UV light or not.  Spoiler, it did, and when she rubbed it in, the whole paper became almost marbled.  Incidentally, Flora assures me that she meant to write “Boo,” although that’s not what I thought it says…  But the bright purple sunblock shows that harmful UV rays were blocked, so yay for SPF50.

Just for fun, we decided to draw on our hands to see if that would work too – it did.  Taking her bedroom door security passes to a whole new level 🙂

Glow with the Flow

Before getting going with this next experiment, we had to make up our dark box – ta dah.  And when I say “we”, of course I mean “me”…

Next, Flora filled all three test tubes with water, emptied the glow powder into one, the glow liquid into another, and left the third with plain water to act as a control.  Then shone her torch down on each of them from the top.

Do you remember the negative charged electrons from our previous Box 4?  Quantum mechanics is when they absorb energy from UV light and become excited.  The glow liquid gives energy back straight away, whereas the glow powder can hold on to it for longer.  And the water control tube shows that electrons have to be in the right chemicals to glow at all.

She also had a go at shining her torch from the bottom, trying to get light to bounce off like fibre optics.   Fun fact: this is how our information travels online: via light beams down fibre optics for the Internet!

Photon Beam of Destruction

This experiment reminded me of Enid Blyton’s Famous Five books.  All you need is the balloons, the magnifying glass and, crucially, a sunny day.  At the time of writing, we’re still waiting for a properly sunny day, so we’ve parked this for the time being.  Once we’ve done it, I’ll update this post – watch this space!

Ultra Colours

This activity was all about photochemistry.  In other words, how the plastic beads absorb UV light and change colour.  Rather than wait for that elusive sunny day, Flora decided to have a go with her torch.  (It’s worth remembering that the Sun is far more powerful than any torch though).

And then she split the beads into two bags and coated one bag with sunblock.  As you can just about see, even through the sunblock, one of the beads has still turned a slight purple (left hand bag).  So that’s a good reason to always wear sunblock even on a cloudy day – as I have found to my cost on the odd occasion when I’ve missed a patch of skin and got badly burnt…

Solar Photography

This was one of the easiest fun science experiments we’ve tried.  Although Flora grumbled about having to cut out Pico, who apparently was much trickier than Meg… But once we’d cut out both and collected a few more objects, it was time to lay them out on the special sun paper.  Then just leave it out in daylight for a couple of hours, until the blue had faded somewhat.

As you can see, the paper that had been covered was still dark blue.  So to fix her design, she soaked the paper in water for a minute.  Rather like a photography fixative chemical.  And when dry, the patterns had turned white.

Solar Powered

Again, this was an activity I remember from my school days.  Growing cress from seed and learning about photosynthesis.  This time Flora had to wet some kitchen roll, add the seeds, and put them away to start germinating.

Side note, I have to say, I don’t remember cress seeds smelling so dreadful while sprouting before – these ones were awful!  Anyway, after germination she moved one lot into the light and left one in the dark.  Can you guess which batch grew faster? 🙂

A Warm Reaction

This experiment was exploring an exothermic reaction, by adding calcium chloride powder to water.  Because chemical reactions can not only give out light, they can also give out energy as heat.

Neither Flora nor Alan claimed to be able to detect any warmth after 60 seconds but I could definitely feel it between my fingers.  Clearly, I’m far more sensitive than either of them…

The Fast and the Luminous

Ah, glow sticks.  Kids love them, don’t they?  This was a lesson in rates of reaction, to measure how quickly a chemical reaction will take and last.  Flora filled three test tubes with water, one from the hot tap, one from the cold tap, and one she’d prepared earlier and put in the freezer for ten minutes.  Then she snapped a glow stick into each tube.

As you can see, the brightest tube was the one in the hot water on the left.  Then the middle tube (cold water), then the right hand tube (freezer water).

Not much change after an hour, or even five hours.  Patience was also the lesson being learned here.

But look – 12 hours later, the hot water glow stick is all but out and the brightest one is now the stick placed in the freezer water.  And after 24 hours, the freezer water one is the only one that’s still glowing.  So more heat equals a faster reaction and a brighter glow, but as the chemicals get used up faster, so the reaction stops sooner.  Top tip: if you want some inexpensive outdoor lights for a party, snap some glow sticks into a few jars filled with very cold water.  Get the kids to help and you’ve got some great fun science experiments too, win win.

Mini-Beast Safari

This was a bonus activity, however, I’m writing this post at the end of December and those bugs that are around and visible, I’m wary of disturbing.  Woodlice, ladybirds, bees and wasps are sheltering, although any snails and slugs I find I throw over the fence into next door’s field 😉

Spiders we see ALL THE TIME though, inside and outside the house.  And I’ve been bitten countless times while weeding and greenhouse pottering so we’ll leave them well alone too.  Come Spring, a Mini-Beast Safari should yield more bug life to record so we’ll park this activity until then.

Final thoughts

So, despite still waiting for the sun to show his face, and for Flora to be free to do all of this Let It Glow Box, we’ve had a blast this time.  If I’m honest, I preferred our previous box, Rocket Fuel, but I know she’s still carrying out lots of fun science experiments with her UV pen and torch.  As Albert Einstein said “Imagination is more important than knowledge,” and this box is clearly spot on.

Huge thank you to Letterbox Lab for our fifth Investigate box.  We’re very much looking forward to journeying into Inner Space to explore how the human body moves next time.

Have you learned anything new about UV light and solar power?  Do you know any kids who’d love to learn new ways to Let It Glow – or more about science in general – with one of these fabulous subscription boxes?

* This post features gifted items but all opinions are our own.