put some baking soda and vinegar into a pop bottle, stretcha a ballon over the opening, the gas resulting (carbon dioxide) will inflate the balloon. This balloon will be a “heavy balloon” it will be filled with gas that’s heavier than air so when you hold it on one hand and another, regular balloon you blew up yourself, then let them go, the regular balloon will float gently to the ground and the heavy one will drop like a stone. But there will be no weight difference that you can feel.
Quick sand in a bucket is really easy to do. Just get a 5 gallon bucket at your local store and put a garden hose and nozzle into the bottom (Home Depot, etc. should have a variety of PVC pieces to piece something together) Fill bucket with sand or probably best to poke holes around the side at a level height, turn on garden hose lightly and you’ve got some quick sand.
Oh - the cornstarch & water thing would be fun. Mythbusters used that concoction on the “ninja walking on water” episode. I think it’s 2 parts cornstarch to 1 part water - mix gently (add food coloring if you want), and watch the weirdness ensue.
You can do this a lot easier than they do–just stick a rubber stopper in, drill a hole through it and push the needle of the bike pump through the cork into the water inside the bottle. It’s easiest if you make tripod fins so that your bottle can stand on its own, too. When my friend and I did this experiment, we put the fins at an angle so the bottle sort of corkscrew-spun in the air.
Another thought. You can set up a motion sensor alarm (you can pick up a cheap one for under twenty buck) and let the kids try to re-enact this episode.
You will, of course, provide your son with either an Akubra or a beret first thing in the morning on his birthday, right? You can’t have a Mythbuster’s party without at least one of the hats!
heh. I think you described the candle one backwards. You’d expect a flame from a lit candle to relight a candle that’s above it. I believe you meant that you should hold the wick of the just-blown-out candle below the wick of the lit candle. Here’s a video. How it works: apparently, the flame of the lit candle ignites the stream of vaporized paraffin coming from the still-hot wick below, travels down the stream, and relights the candle.
How about an egg drop? Come up with suitable materials, and have the kids build something such that you can drop an egg from, say, ladder-height without breaking. Possible materials include toothpicks, popsicle sticks, paper, straws, pantyhose, tape…just give your teams the same stuff so it’s fair. Kids that age love going crazy with scissors and glue and whatnot.
As a parent, do remember that a lot of these experiments are messy sticky things.
I’d suggest the kids wear swimsuits and bring a change of clothes. And maybe have a party that goes “science, cake and presents, run through the sprinkler so you aren’t quite so sticky when you get into Mom’s car.”
Thread Necro! I wanted to thank everyone who posted suggestions. The party was a big hit, even though only a couple of kids could come. The adults sure had a great time! I also wanted to share some pictures, if you’re interested.
