Liquid Nitrogen!

[Redmoo]

Ok, so I have to do this talk to a group of school kids aged about 14-15. Yay for me! Anyways, thought that I would ask what kind of demos kids that age would be interested in with either LN2 or dry ice (solid CO2). of course the freezing banana and flowers etc are down on the list....I have loads of other ideas but I wondered if anyone had either seen one or even better given a talk themselves!

 

Any input is appreciated

 

Adam

[sym170]

dry ice explosion!

where do you get dry ice from? can't find it anywhere:s

[Fluffy-lou]

I used to teach secondary science. Rather than me droning on about how exciting science is and boring the pants of everyone here, pm me with the brief for your talk and I'll see what ideas I can come up with.

[MattPlanet]

The balloon thing is pretty cool. Watching it re-inflate as it unfreezes looks crazy. I'm sure there's some science behind that as well

[cwatson]

pack a 500ml coke bottle with dry ice put the lid on and throw it quick.

 

SORTED

 

check youtube for vids

[Capt Slog]

I do.

 

I've done a 'science night' at scouts a couple of times, and I used to take part in science lecture demos at the uni I worked at as a technician.

 

I did the usual stuff like freezing bananas (and then making them into the head of a hammer and knocking in nails), but I used to 'specialize' in chemiluminescence.

 

I don't know what your background is or what materials you have to work with, but if you'd like to chat you can PM me I might be able to give you some more ideas.

[Fluffy-lou]

The balloon thing is pretty cool. Watching it re-inflate as it unfreezes looks crazy. I'm sure there's some science behind that as well

 

Ideal Gas Law... PV = nRT

 

Told you I'd bore you.

[Munky Boy]

Get the school bully and pop his head in it. Job Done

[sym170]

pack a 500ml coke bottle with dry ice put the lid on and throw it quick.

 

SORTED

 

check youtube for vids

ah but where can ya get the dry ice?

[Redmoo]

I work in a research lab that specialises in pyrophorics (they are even more fun than LN2 and dry ice ). I have plenty of dry ice and LN2 so thats not a problem.

 

I will send PMs tomorrow as work has finished now and im off home

 

As a quick overview, we are a chemistry manufacturer that has offered to help out at one of the local schools. Its meant to be a fun demo with a basic science background (explaining how a very cold liquid can be boiling etc). I cant do anything 'to' dangerous as its indoors (which kind of rules out the coke bottle ) but so far I have ping pong balls, balloons, eggs, rubber gloves, blu tac, rubber tubing and hot dog sausages (stick hot dogs into a glove and then put 'your hand' into the LN2. Procede to smash with hammer).

 

All I have done all day is freeze balloons and various fruits And people say science isnt fun

 

Adam

[Dick]

You could set up a simple series circuit with a battery, a couple of wires and a bulb and then freeze the battery so the bulb goes out, then leave it to melt so the bulb comes back on.

If you can get your hands on a superconductor there's a lot of Lenz's law related fun to be had too.

 

Dick

[Afro1599968737]

If you can get your hands on a superconductor there's a lot of Lenz's law related fun to be had too.

 

Dick

 

yup, levitating magnets all the way, but then its hard getting hold of superconductors

[dmb]

Just re-reading Chuck Yaeger's biography atm, he tells the story of the first time he saw the liquid oxygen used to fuel the X-1 plane he broke the sound barrier in.

 

One of the techies demonstrated the effects/dangers of low temperature liquid gas by dipping a frog in it and dropping on the ground, where it broke into five bits

 

Maybe not suitable for a kids demo these days ... keep them awake though (probably all night )

[angus8ken]

One of the techies demonstrated the effects/dangers of low temperature liquid gas by dipping a frog in it and dropping on the ground, where it broke into five bits

 

Maybe not suitable for a kids demo these days ... keep them awake though (probably all night )

 

nice one! you could get the class to all bring a pet in

[Chip_Slog]

lol yeh i think the teachers might just object to the frog!!

(which kind of rules out the coke bottle ) Adam

thats a bugger, thats always good fun but i strongly suggest the school bully idea

 

the only other thing ive got is putting the dry ice in a sports bottle with water (the ones with the little pushy lid things) stand it on its end and wait for it to blow upwards like a rocket! though probably not very good for indoors!

[Big Dog]

You need to make some fins to keep the bottle straight surely?

[Redmoo]

'Cooked' an egg yesterday. Thats kinda fun I want to get hold of one of those big punch balloons Fill that with CO2 and see how big it gets before it blows!

 

I have a few weeks to organise this so Im going to keep playing around....er....I mean doing valuable research

 

Adam

[iant84]

I was giving Liquid Nitrogen demos to 14-15 yr old kids at uni on Monday! Small world it's part of the open access to all program or somethnig along those lines. Cool tricks to do are to get a bowl of hot tap water, pour in some fairy liquid and then pour in a couple of cup fulls of liquid nitrogen, you get a really cool effect with huge fairy liquid bubbles filled with smoke.

 

The other demos we did were, pouring it into an old style kettle so it boils inside making it whistle, get a ping pong ball, pierce a hole in it and hold it in the nitrogen, it fills up and when you take it out it'll spin round like crazy, a potato cannon using liquid nitrogen, smashing a lettuce and the best of the lot, making ice cream! (mix custard, sugar, cream and flavours (strawberries are great this time of year) into a bowl and pur the nitrogen in whilst stirring, it takes about 3 minutes, put the mix on a cone and enjoy)

[Redmoo]

I cant get the ping pong ball to work! It just sprays liquid everywhere instead! I have tried using different size holes and as they get too big it just kind of pffts about. If the hole is too small it wont fill up!

 

The bubbles is a good one though Want to 'float' a bubbler on a bed of CO2 as well, just need a glass tank big enough

 

Adam

[Neil aka KC]

pack a 500ml coke bottle with dry ice put the lid on and throw it quick.

 

SORTED

 

check youtube for vids

 

LOL our chem teacher used to tell us he did something like that when he was a kid. Back then he said ice cream vans used to carry the stuff to keep the icecreams frozen etc, he used to get his hands on the stuff and put it in milk bottles.

[JimC]

Take the kids into the playground put some dry ice in chips and feed them to pigeons.

[Chip_Slog]

You need to make some fins to keep the bottle straight surely?

yeh cant remember if we used any (only done it a few times n quite a while ago) or u can just leave it as it is n it spins off in any random direction

[Anne1599968726]

I saw a good one done with rubber tubing (like off bunsen burners) was particularly good because it was done in front of a large crowd - easier for the folk at the back to see.

 

What she did was get the rubber hose, bend it/stretch it etc to show how flexible it was in normal room temperature....

 

Then dunk in the the liquid nitrogen... bang it off the desk, shatter a bit off the end with a hammer etc .....

 

Then let it warm up again and do the "look its all bendy and stretchy again" bit

 

 

(well I enjoyed it )

[Redmoo]

Its even better if you have it open at one end....makes a LN2 spray cannon which you can then point at people They get pretty scared even though its harmless

 

Adam

[Afro1599968737]

see if you can put a pet in stasis !

c'mon that would be very cool, aslong as you dont drop it.

 

or, very cool as well...

 

get a water pistol and two buckets; make a hole in one bucket so the liquid nitrogen streams through to the other, then shoot the water pistol throught the stream & form a jet of ice !