Alka-Seltzer Rocket Man

So, Science Week has come and gone. In the end I decided to go for the simple fun of the Alka-Seltzer rockets!

Because film canisters are so hard to come by these days I had to wait until about half an hour before the experiments were due to begin to test out the methods... We had a choice between Alka-Seltzer + water and baking powder + vinegar - because I didn't want to get stinky vinegar over me before the whole thing started I only tested the Alka-Seltzer rockets, and that was less than inspiring. Not looking good early on! But no time to change things.

I've spent a lot of time with this particular class over the last year and a half, but they were very surprised when they came back to the classroom and saw me there in my lab coat! Naturally there were quite a lot of questions (mainly about exploding things!), and I think they were quite excited when I said I'd studied Science at uni.

To start with I decided we should stay in the warm and check how much they knew already; I was quite impressed that a few of them knew about carbon dioxide, and could tell me about how baking powder works. They were also pretty good at describing what was going on in the glasses when I tried the two combinations out for them all to see. So a promising beginning!

The fun part began when we went outside and did some demonstrations... Varying success, but it worked more often than not - and definitely got a few laughs when it took off quicker than expected!

The challenge that we set them was to get the rockets taking off as close to 60 seconds as possible. I'm not sure that they really understood the effects of changing the different variables - even when I kept asking if they were sure that what they wanted to do was right! They probably were just enjoying themselves too much to think about all the science going on! And if it gets them interested in the subject, then who am I to complain?

Before we froze to death outside we just had enough time to make a baking powder & vinegar volcano too!

The last thing they had to do was a brief write-up of the 'experiment'; some of them were more worried about drawing the rockets well than getting on with writing, but I'm quite capable of chivvying children along! Long words and everything!

It may have just been a short time spent in school (ideally I'd have liked to have come in on a few more occasions to see other experiments), but it was definitely worthwhile - and very encouraging seeing how interested they all were in it. Especially when one boy told me he has a chemistry set at home! There's a long way to go, but hopefully there's a handful of future scientists in Somerset...

Try it yourself! All you need is:

Alka-Seltzer tablets

Water

Film canisters (or similar)

Initially try filling the canister about two thirds of the way up, and add a quarter of a tablet.

Make sure you add the tablet quickly, put the lid on and turn it upside down.

Time how long it takes to lift off - and alter variables accordingly.