What is the equation for this reaction?

Question

If you put an electric current through water, you can break it into hydrogen and oxygen gases. What is the equation for this reaction?

H2O --> H2 O

2H2O --> 2H2 O2

2H2O --> 2H2 2O

2HO2 --> 2H2 O2

Answer 1

I assume this is multiple choice.

Because both Oxygen and Hydrogen are diatomic (travel in pairs) when in their natural state,  the correct equation is :

2H2O-->2H2 +O2

Answer 2

H2O -> H2 + O2

have 2 Oxygens on the right, only have one on the left, so need to have 2 on the left

2H2O -> H2 + O2

now have 4 H's on the left and only 2 on the right so need 2 more on the right

2 H2O --> 2 H2 + O2