[western50]

Batteries always have two terminals, labeled + and - . The + terminal has the higher electric potential. If you connected the terminals to a circuit, which way would positive charges flow in the circuit? What about negative charges?

My thought to this is that the current flow from area with high electric potential to area with low electric potential. I think that the positive charges would not flow and stay still in the battery, but the negative charges would flow from + terminal to ' terminal due to the electric potential difference.

Is this correct? Please correct me if I said something wrong.

[ebaines]

Not quite. Back when electricity was first being investigated the scientists of the day were unaware that in reality electric current consists of - charges only. So basically all the common conventions that were established at that time assumed that electricity flow consisted of + charges, and hence that positive charges flow from the high potential + terminal of a battery to the - terminal. We now know that they got it backwards, that in reality electricity flow consists of negatively charged electrons flowing from the - terminal to the +. But mathematically it doesn't matter whether an electric circuit is modelled as + charges flowing one way or - charges flowing the other. So even today electrical engineers talk about current flow as if it consisted of + charges, because that's the convention that is well established.

Here's a site that illustrates this nicely: Electricity and the Electron

[zanderbaxa]

The direction of electrons flow is from negative(-) to positive(+) outside the battery (EMF source). In the battery the electrons flow (+) to (-). Essentially, (*) is an excess of electrons and (+) is a deficiency of electrons. Another way of looking at it is the hole theory (which is related to semi-conductors). What it says is that when an electron is moved it leaves a hole; so the holes are (+) entities and flow opposite to electronns.