This reminds me of when I was doing this for my daughter, because she had all the instructions. They'd done it in school and, you know, when you mix bicarb and vinegar, I mean, they're just things you've got in the cupboard, in the kitchen, and...

Let's put the witches' cat in the t-- green slimy swamp. If it floats, it's a witch. If it sinks, it's a witch. That doesn't make any sense to me, what you've just said, but I'll--I'll--, again, I'll take your word for it, mate. You've actually created casein, which is Latin for cheese. The casein in the milk does not mix with the acid in the vinegar, so it forms blobs. You fill the plastic bottle three quarters full with water and a few drops of INTERRUPTION washing-up liquid. I loved science. I loved all the experiments, to be honest. Any time I had to put a lab coat and LAUGHS put the glasses on, put a Bunsen burner on, I was in heaven.

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When the three skewers meet at the top, use a bag tie to tie all three skewers together close to their ends. Now if you've got children in the house and you've tried to bake a cake recently. Have you done that?

Yeah, exactly. So let's have a look. Let's compare these balloons. So I had, uh, two balloons on my car. And it gave a bigger push. So your prediction has been proven. That is so cool. INTERRUPTION It is actually working even INTERRUPTION though we put it in afterwards. It's very cool. The negative charge on the ballon or comb attracts a positive charge in the water so pulling the water closer. Rice is slightly elastic and so eventually when the blade is pushed in, the compact grains will bend tightly against it, allowing you to lift the jar using only the handle of the knife. Take the bottle outside and connect the pump to the needle adaptor. Ours wouldn’t stand up on the fins so we rested it on a box, but if you make some strong fins it should stand up by itself.

Each time the handle is pushed into the rice, the friction increases, opposing the force of gravity.

I did some stuff with Blue Peter which ended up as a complete disaster, glitter everywhere including in the camera lens. I didn't expect it to fly so high, I've gotta say that. But, it's just a little tweak, Trevor, that's all it takes sometimes, a little tweak. As air escapes from the balloon it is pushed through the holes you make in the bottle cap and the CD in all directions because of the shapes, smoothness and weight distribution of the hovercraft the escaping air creates a thin cushion between the CD and the surface. The cushion of air dramatically reduces the friction between the CD and the surface and allows yourI think, uh Cherry's going to be good at doing the experiments. We, we see quite a lot of that, uh quite often certain things going-- mishaps and going wrong. A bit. Where's your face? There you go. So you come up trumps there I think. Right, let battle commence. Push your third marshmallow onto the tied end and make a mark on this marshmallow. And, make a mark on it. Put an X on it. If you repeat it several times more will get transferred. You now have tiny amount of static electricity on your ballon.