Lets make hydrogen and blow up the kitchen.
Not that we got enough to actually blow up the kitchen, but it did go bang.
Me and Dad did an experiment that makes hydrogen and oxygen by separating water into it's component atoms.
You collect the oxygen & hydrogen in test tubes or some other small receptacle, and then light a match and ignite the hydrogen.
The last part wasn't part of the experiment, but it was fun :)
The photo is of the copper wire we used, it got corroded by the oxygen.
- Fujifilm FinePix HS30EXR