Q1
You may have a look on this
電位差是透過氧化還原電勢建立的
電位差 => 電場 => 電子流動
Q2
A flow of positive charge gives the same electric current as an opposite flow of negative charge. Thus, opposite flows of opposite charges contribute to a single electric current. For this reason, the polarity of the flowing charges can usually be ignored during measurements. All the flowing charges are assumed to have positive polarity, and this flow is called Conventional current.
In solid metals such as wires, the positive charge carriers are immobile, and only the negatively charged electrons flow. Because the electron carries negative charge, the electron motion in a metal is in the direction opposite to that of conventional (or electric) current. While it would make more sense to draw current arrows in the direction of what is actually flowing, convention dictates that this not be the case.
