How can we separate hydrogen and oxygen from water?
Through electrolysis (Safety Warning: Don’t do this without an adult present). Basically what you would need to do is run a direct electric current through a cup or bowl of water using a high powered battery or an outlet source. Now as the current passes through the water and breaks down the molecules, hydrogen will bubble from the cathode (which is the positive side) and oxygen will bubble from the anode (the negative side). For a better effect, us salt water since the salt raises the conductivity. Now, the anode may not produce a lot of oxygen depending on what type of metal your using; platinum works best… anything else will either just dissolve or oxides will be produced.