 Welcome to Do Try This at Home brought to you by the Institute of Physics. We're making these films because we want to help parents and carers in the UK and Ireland get their kids excited and curious about the world around them and you don't need to leave your home to do it. My name is Lucy and you're very welcome to join me again in my home. This time I've moved to the kitchen and I'll be doing a new demonstration called the Electric Balloons. I love this demonstration because it takes something that we're all familiar with in some way. In this case rubbing a balloon on a jumper or on our hair. And it does that something a little bit extra with it. It should be a positive experience for everyone, especially if you've been left in charge of the family for the afternoon. For this demonstration you'll need two balloons. You'll also need string or you can replace this with wool or thread, basically anything that will help you hang the balloons. You'll also need some sellotape and you'll need a woolly jumper or you could use a cloth or you could use your hair or you could try out a few other things. To get started we're going to blow up both the balloons and tie them. One balloon done. Next we're going to take our string and we're going to tie it around the knot of the balloon. Alright we're going to find somewhere where we can hang the balloons. You could do this over a door frame or from some hanging lights or as I'm going to do over my cooker. So I've hung both my balloons from my cooker but you could also hang them from the middle of your door frame or from some hanging lights wherever you feel is suitable in your house. The important thing to remember is that the sides of the balloons are just touching when you let them hang straight down. On the spot where the balloons are touching we're going to rub each balloon with our jumper, a piece of cloth or our hair. You can try different things around the house to see what gives you the best results or you could follow my example because I'm going to use a glass. Bringing the sides of the balloons that we've just rub close together and this time you'll see that the balloons move away from each other. So what's going on here and how can you explain it to your family? The interesting physics happens when we rub each balloon. Pretty much everything you come across is made of atoms. If we zoom in every atom has a possibly charged centre with negatively charged particles called electrons around it. Each atom has the same amount of positive and negative and these charges cancel each other out. When we rub two things together we're moving electrons from one material to another. Is this something you've seen done before? You might have made each other's hair stand up on end like this. My hair is pretty rubbish at holding onto its own electrons and the rubber of the balloon is quite good at it. So when I rub the balloon with my hair the negatively charged particles are rubbed off my hair and onto the balloon. As more and more electrons get built up on the balloon the whole balloon develops a negative electric charge. My hair has lost electrons and it has the opposite charge, a positive electric charge. Opposite attract. So when I lift up the negatively charged balloon my positive hair lifts up as well. What about the two balloons? When I rub the balloons they both end up with a negative charge and they certainly aren't trying to get close to each other. Materials that have the same electric charge repel each other which is why these balloons keep their distance. Don't worry if you're unsure about the science though. As always have fun together, test it out together and then look it up together if you need to. Thank you for watching and see you next time.