0.5 amp per square inch of both +/- plate or just one plate?

[needanswer]

sorry for the newbie question.
I see the 0.5 amp per square inch quoted often here.

If I have two plates , one + and one -, each plate is 1 square inch,
does that count as 2 square inches and run 1 amp through it or
is that just 1 square inche and run .5 amp through it?

also , is this the point where running more amps would just heat water?

thanks.

[needanswer]

also, how much gas (liter/min) can you expect from 1 square inch running 0.5 amp?

that way, I could figure out the electores I need.

thanks

[Bob Boyce]