How can I separate water into its main elements for a science project?

[AfterShave]

Hey Guys. I am new here and I need help with a science project. I am in 9th grade and wouldve posted in the 6-12 room, however nobody k-12 would know how to do what I need to know how to do. So this is what I need to know:


As part of my science project I need to separate water into its main elements, which everyone of you should know are Hydrogen and Oxygen.
That part I know how to do. The part I do not know how to do is getting oxygen on one side and hydrogen on the other. So here's my theory. I believe Oxygen weighs less than Hydrogen. So if we apply enough pressure to just keep the oxygen on the bottom then the hydrogen will flow up. Could this work, and if so, could anyone help me out with it. And if anyone has a better idea on doing this feel free to tell me. Thanks

AfterShave

 

[catch.yossarian]

look at your periodic table and check again to see if Hydrogen weighs more or less than Oxygen.

I believe Oxygen is heavier.

I'm not the best with this sort of stuff, but I believe you'd have to add something to separate the H2O. Since H2O is two hydrogens and an oxygen connected during the solid, liquid, and gas phases - you'd have to add some other chemical into pull the Hydrogens and Oxygens apart from one another and cling onto this 3rd chemical.

Maybe then from there you can do something with it.

 

[HallsofIvy]

That's a standard experiment. You separate hydrogen and oxygen by putting electrodes into (salted) water and running a current through the water. Since hydrogen ions are positively charged they will be attracted to the negative electrode while the negatively charged oxygen ions are attracted to the positive electrode. Put a test tube full of water over each electrode and collect the gasses in them.