26 replies to this topic

[phildunford]

For my sins, my school wants me to run a series of practical 'Science Clubs' (4 1 hour sessions after school - 1 lot for year 7 one lot for year 8 and possibly another lot for gifted and talented) about the science of fireworks.

Now I have quite a few ideas of my own, but I'd be interested to see what you lot have to add.

1) We are talking 11-13 year olds, so it's got to be interesting, simple and fast-moving or I'll loose them...
2) Got to have lots of practical experiments the kids can do themselves (in a school science lab or grounds).
3) Need some spectacular demos to end with.
4) We have a budget, but only a modest one.
5) Groups of about 12 kids.

I'm also sure you can put forward 101 reasons why I should not be even thinking of this, but I'm more interested in hearing practical things I can do...

Over to you!

[Arthur Brown]

First, get the buildings manager (head caretaker!) onside most things will be smoky enough to fire the alarms -even in neighbouring rooms!

Flame colours
Red Lithium and strontium
Yellow Sodium
Green Copper

Spectral emission is due to thermally energised electrons falling back down to a ground state releasing a quanta of energy -hence the spectral purity. Planck equation? Energy relationship to wavelength and planck constant. - I'm not really sure what is year 7 science level

All aided by a Pt wire dipped in HCl

Burning under water
lacquered visco
- proves that the compound contains fuel and oxidiser

Small sample of BP in a tt with a delivery tube to determine the volume of gas produced by a solid

Small amount of whistle pressed into an open tube to make a noise

KClO3 and Fe burned to give oxygen

Tell us;
Are they going to learn formulae or is that to remain a dark art?

Who has all the recent TV series on disc. Can you pull all the experiments from that.

Tell the parents that for £2000 you will take them to China (For £4000 you'll leave them there!).

[phildunford]

Tell the parents that for £2000 you will take them to China (For £4000 you'll leave them there!).

Lol - that could prove popular!

I see no reason why they should not know formula. Any kid interested enough to actually make something can find them all on the internet - I'd rather they saw how to do it safely. For the kids who are not going to go to the trouble of making things, it can do no harm.

I have episode 2 & 3 of the series, but not episode 1 - if anyone recorded it I'd be most greatful for a copy.

I've also had a re-look at Colonel BB Shaw's explosive lecture, but most of it is a bit large scale for a normal lab.

Thanks for the ideas Arthur - keep them coming chaps...

[Arthur Brown]

www.teachers.tv/
http://www.teachers.tv/video/20297
http://www.teachers.tv/video/12099

Have you a copy of "Kaboom" the Equinox programme

[Mortartube]

You don't just have to stick to using pyro of course. You could make a water rocket using a lemonade bottle and a car foot pump to demonstrate rocketry and of course inflate a balloon until it bursts to explain the same principle that makes exploding fireworks work, but of course you have to have some pyro as well. It would be rude not too.

If you can get some gas jars filled with oxygen, you can of course introduce heated metal powders such as iron filings to then explain that nitrates etc contain oxygen which they give up easily in a firework reaction.

[digger]

How about an ammonium dichromate volcano. It can be used to demonstrate several chemistry principles decomposition, density etc etc

[paul]

How about an ammonium dichromate volcano. It can be used to demonstrate several chemistry principles decomposition, density etc etc

You can tell them about toxicity as well, then

Edited by paul, 06 April 2009 - 04:39 PM.

[Arthur Brown]

Get a small headless rocket - commercial! Weigh it, put it on some scales and light it, plot thrust against time and then introduce the equations of motion s=ut + 0.5ft^2 and others and plot the height you expect the thing to peak at and all the other parameters. Go into mass and velocity through the choke to give thrust. possibly no need to go into the way that BP increases burn speed with pressure.

Simple plotting thrust vs time involves a video camera and slow mo play back, a single frame is 1/25th of a second at normal rate, your school may have data logging PC based kit if you ask!

[digger]

You can tell them about toxicity as well, then

That is what fume cupboards are for

[Arthur Brown]

NI3? Someone's got to show them how to be a nuisance!

[crystal palace fireworks]

Phil,

Are the experiments going to held both indoors and outdoors? and do you have access to perspex demo cabinet (as in video www.teacher.tv)?

Edited by crystal palace fireworks, 06 April 2009 - 09:12 PM.

[defective]

you could demonstrate the oxidising power of KClO3 by melting some in a boiling tube and inserting a gummy bear or jelly baby!

[phildunford]

Phil,

Are the experiments going to held both indoors and outdoors? and do you have access to perspex demo cabinet (as in video www.teacher.tv)?

Hi Keith,

Pretty comprehensive facilities are available. All labs have fume cupboards.

My general plan is to start the session in the lab and then go out to the field at the end to do something big and spectacular!

[Mortartube]

Hi Phil,

Actually one thing a friend of mine used to do (he works making power supplies), is take an entire roll of toy caps. Tear it in half and lay it face to face with a nichrome wire running through the middle and poking out of each end. Encase it in heat shrink sleeving which you carefully shrink on it with a paint stripper gun. The apply a good voltage across the wire (at a safe distance outside). It is rather exciting and produces a good crack.

If you keep the heat gun constanly on the move and on its lowest setting, it is not as troublesome as it may first appear.

Of course don't let on what is actually in the heat shrink as you don't want them trying it at home. But it will demonstrate what fast expanding gas can do.

Defectives idea of the jelly baby is good. I spoke to a chemistry teacher who does this in a boiling tube. He makes a little gallows out of splints to lower the jelly baby in. The kids love it.

[crystal palace fireworks]

Phil,

You could do the`Mento`s sweets in a bottle of cola routine, or show how a laser pen can burst a balloon, (I guess you will need to adjust the diode intensity),...same principle on the old magnify glass and insects thing we did as a kid.

Just to add to mortartube water rockets idea,......you could perhaps measure the pressure of escaping water from the launch bottle by directing the water into a large syringe/plunger,..... which in turn pushes air out into the mouth piece of a homemade airhorn (latex rubber sheeting is used),.........Im sure I have seen these handheld rave party air horns for sound somewhere!

helium balloons with coloured smoke, or perhaps some Koom Fays with chinese crackers tied to them could be launched from a post.

You could make a mini bonfire in 20 a litre can (old cooking oil can will do) and then show the kids the actual different colour flames you can make by adding strontium or barium cakes, or fire rope,...get the kids to design and make a message on some chicken wire,.......you then add the petrol mix comp.