Hey everyone! I'm Greg Foot. I'm a YouTuber and the science guy on Blue Peter and I'm
here with Mumsnet to show you four marvellous science experiments you can try using stuff
that you already have lying around at home. It's British Science Week so we've teamed
up with Puffin Books, who are launching a new book which is a companion to George's
Marvellous Medicine by Roald Dahl and it's this- George's Marvellous Experiments. It
is packed full of try-at-home demos that you can do with kids and your family by Roald
Dahl's favourite scientist, George Crankie. Let's Dive in.
This first one is a messy one. It's foaming fizzy potion. Take a cup. Make sure it's a
tall cup. Put a bit of water in it, probably about that much and then take some bicarbonate
of soda and put a good old spoonful. You want a bit of food colouring. Pop! Like that. Big
dollop of washing up liquid, lemon juice. Woooo! George's foaming fizzy potion! Look
at that. Now the reason this works is because of two ingredients that we've got in there-
bicarbonate of soda and the lemon juice. The bicarbonate of soda is what we call an alkaline
and the lemon juice is what we call an acid and when you mix an acid and an alkaline together
they react and one of the things they produce is a lot of gas, a lot of carbon dioxide gas
and that gets stuck in all the bubbles of the washing up liquid and has nowhere to go
but out. There we go. Next up is rainbow rain. So for this you need
a tall glass fill it about two thirds of the way full with water. Then you need to get
ahold of some shaving foam and put that on the other third. Great noise! That is going
to be your cloud. Then mix up three different colours, well actually you can go crazy and
do as many as you want. I've got some red here. You want to add that to the top. Now
you can pour it on nice and carefully. I prefer using one of these little pipettes. So that's
the red in. Let's go for the green. Green goes. Nice! A bit of blue. Yes! The rain has
begun. Look at that! So we've got blue rain, green rain, a little bit of red will be joining
it soon and this is actually so similar to how rain forms out in the real world. If you
took those big fluffy clouds you see out on a gorgeous day and you've rung out all the
water, the weight of all that water is the same weight as 100 elephants. Yeah, that's
how much water there is in a cloud but because its such little drops they don't fall but slowly
they bump into each other and get bigger and bigger and that's the same here. All of this
food colouring starts building up and then eventually falls down as rain.
Next demo that I've chosen from George's Marvellous Experiments is directly inspired by Roald
Dahl's George's Marvellous Medicine. There's a line in the book where George has made this
potion and he looks inside and he sees swirling flecks of colour dancing around so that is
what we are going to recreate. Ok, we need some milk and a plate and put your milk onto
the plate. Don't put much on, just so that it covers the whole of the bottom of the plate.
Then you need some food colouring and the best thing for this is to use a pipette and
just put on some big dollops of colour like that. Then take some washing up liquid. I
like to put a little bit on my finger and then pop it. Yes! Look at that. The blue and
you can kind of chase it round, it starts swirling in itself and you get these great
patterns. So what's happening here is that every liquid has a skin on the top. And its
not an actual skin like custard but you can think of it as all the molecules gripping
together. It's called surface tension and when you put the washing up liquid in it breaks
the surface tension and anything on top of it, all that liquid, goes flying.
So the last demo I've chosen from George's Marvellous experiments is a novel and new
way to inflate a balloon and it needs this stuff. Let's see if you can tell what it is.
*Crackle* can you hear that? *Crackle* You must be able to hear that. Popping candy.
Everyone's favourite treat from the 80s, love it! OK, you need a good few packets of it.
I find its helpful if you empty them out into a cup first, and you're gonna need your balloon.
Now, the best thing to do is to make a funnel from a piece of card or paper. Just wrap it
round on itself and stick it with some tape. put that into the balloon like this, then
pour in your popping candy. Now what you need to do, take the lid off a fizzy drinks bottle
and put it over the lip of the lid. Don't let any of the popping candy go in. I like
to secure it with an elastic band. To make the inflation happen you just need to lift
this up and drop the popping candy into the fizzy drink. Three, two, one go... make sure
it can drop out. Oh its starting to go in. oh it's good! Sometimes it gets a little bit
too excitable, then it just fills with foam. So popping candy pops because it's made of
lots of sugar but it's what's inside that matters. There's a gas inside called carbon
dioxide. You eat the popping candy, the sugar melts essentially and that carbon dioxide
gas pops out but here it's going into the fizzy drink and releasing that gas and its
also releasing the carbon dioxide that makes the fizzy drink fizzy. That released gas comes
up and fills up our balloon. So there you go! Four of my favourite demos
from this brilliant new book, George's Marvellous Experiments. Please do go check it out. There's
also a new edition of Roald Dahl;s George's Marvellous Medicine as well. And as I said,
this is British Science Week so there are events up and down the country go and search
for that. It runs from the 10th to the 19th March. This is Mumsnet YouTube, hopefully
you are already subscribed, if not hit subscribe then the bell next to it then you get a notification
every time they put up a new video. And also like and share with your friends. My name
is Greg Foot and if you want to see more of what I do go and check out gregfoot.com. Thank
you very much. Goodbye!