Electrolysis

Electrolysis is the separation of water, but it can also be thought of as the conducting of electricity through water. Electrolysis is simple:

1. Do this outside because this creates a small amount of chlorine, which is toxic in large amounts, if you're using salt and a small amount of ethane, what most people know as "natural gas" when used on gas stoves, this stuff is explosive when mixed with air in large amounts. Both of these also create hydrogen, which is also explosive when there is a very large amount of it. You will be safe as long as you don't breath a whole over the reaction.
2. Add a small amount of salt or vinegar to some water in a small glass that you either don't care about or got from the dollar store
3. Get a AA, 9V, C, or D battery and attach a copper wire to each side using tape (Electrical or duct tape work best)
4. Take the two wires and stick the ends in opposite sides of the water.
5. From the side, watch the ends of the two wires.


You should notice the wires bubbling, the negative (cathode) side bubbles are made up of a gas called hydrogen, and the positive (anode) side may or may not have bubbles coming off of it. If there are it is oxygen. If there aren't it is because the oxygen that is being produced it combining with the copper to make copper oxide. And oxide is a combination of oxygen and a metal, iron oxide is iron and oxygen. You probably know of iron oxide by the name of rust.

The bubbles are formed because the electricity tears apart the water, which is made up of two hydrogen and one oxygen, into its two pieces. If you look again at the wires, you will see that there is more hydrogen than oxygen. This is because water contains twice as much hydrogen as oxygen, that's why we call it H2O, because it has 2H (hydrogens) and 1O( (oxygen).