Fantastic stuff! Going to use many of these for sure. I totally forgot about the egg in a bottle trick and getting it out again. My dad used to do that one and the can one that I mentioned when I was little. He was a science teacher. 
BTW Szlater - I am agreeing with you there.
I’m sorry I confused this thread for another current thread about ideas for lessons in 6th grade science, I forgot this thread was about a birthday party.
Parties ARE about entertaining the kids, d’oh!
I still want them to learn something lol
Timely thread-the mother of twins I teach just gave me carte blanche to recommend almost anything for them.
A chunk of Sterno fuel in a fire-safe plate, and shake metal filings over it to make different colored sparks. We had Mad Science come to my son’s 9th or 10th birthday party and that was one of the things they did.
It’s really easy to extract DNA from various fruits and veggies and show it to the kids. The DNA looks like clearish-white strands of stuff floating in a drinking glass or test tube. I’m too lazy to look it up right now, bit if you google up “extract DNA from an onion,” you’ll get clear directions on how to do this with common household stuff, along with an explanation of what each step in the procedure does.
Kids are usually pretty wowed by being able to see DNA with the naked eye!
You just need salt, dish detergent and vodka, I believe.
Onions are an ideal subject.
Meat tenderizer helps, too. And, yeah, you can use vodka, but if you can get Everclear, or 100% ethanol from a pharmacy, that will work even better.
Whatever alcohol you use, make sure it’s as cold as it can get before you start. Put it in the back of your freezer the day before you want to wow kids with your Dr. Frankenstein skills.
Oh, and you need a blender, a small turkey baster or disposable pipet (the pipet works better), and an old t-shirt or other piece of cloth you wouldn’t mind using as a strainer.
Here’s some more info on how to get DNA from an onion, such that you can see the DNA itself:
http://www.biotech.iastate.edu/lab_protocols/DNA_Extraction_Onion.pdf
Let us know what you end up showing the kids.
Try this, and tell me if it works (because I’m too lazy to go shopping myself, really).
Go to a health products section/store, and see if they have Lycopodium powder. Get the purest they have.
Light a candle, pile a bit of the powder on a surface about level with the flame and blow the powder into the flame. Whoooosh fireball. Burns fast and bright and is unlikely to set stuff on fire, though be careful, obviously.
This stuff definitely works with pure stuff from VWR and Aldrich, but I’ve never tried it with regular store stuff, which is why I want a report back
If it works, do this:
pile powder into your hand, at the front of the palm near your fingers. Light a wooden match (safety match) and stick it between your fingers, flame upwards. Hold your hands up high and then drop them quickly. You’ve just thrown a fireball.
I’ve seen a papier-maché dragon on the same principle - paint can in the mouth, hose to blow into, powder blown into the flame. Scared the crap out of kids and was amazing. The classmate who made the dragon was very good and it was quite lifelike, for papier-maché!
Alcohol and water, 50-50 mix. Dip a dollar bill…or hundred dollar in it…light it on fire. Return the bill to the owner, intact and undamaged (thought possibly a little damp).
That’s the one I came in to recommend. I think I would have loved it at that age. (OK, I still love it at 50)
Any fine powdered carbohydrate will work. Icing sugar, potato or corn starch. You just have to mix it with enough oxygen (by blowing) to get the rapid burn.
I haven’t tried it over a candle, but powdered coffee creamer is excellent tossed over/into a campfire.
Yeah I’ve seen that done too.
We did it at secondary school with Bunsen burners and glass tubes filled with various powders.
Squirt bottles with various metal salts dissolved in water is another great pyro demo, and then you can talk about electron orbitals and photon emission.
Heating a tin can, stoppering it and then dunking it in an ice bath is a good demonstration of air pressure. As is the newspaper over a wooden metre stick, hitting it with a hammer breaks the metre stick because the air pressure on the surface area of the newspaper.
An old Science Digest from the 1950s told how to makw yourself a miniature grain elevator explosion using a galvsanized tub with a lid, a funnel full of flour connected to a rubber hose, and a lit candle. I wouldn’t recommend it for a party of 10 year olds.
The best demo I ever saw was the blowing up of two pianos. The first piano got a 1lb or so of a high explosive, and was badly damaged. The second got an identical amount of high explosive but this was placed inside a largish bag of flour. The second piano was utterly destroyed in an enormous fireball. It was the most amazing science demo to my 9 year old self.
But not really suitable for a birthday party.
I’ve done this, and IMO, it’s going to be a bit dry for 9-10 year olds. By 13 or so, they know what DNA is, and they can appreciate that those unimpressive clumps of white threadlike stuff in the test tube is actually THE STUFF OF LIFE!
And even then, it’s more exciting on the level of a mildly cool science lab, than a raging party show.
A 9 year old is going to see (after 15 boring minutes of pouring clear liquids into tubes, and back out) unimpressive clumps of white threadlike stuff in a test tube.