【IS】Electric current (電流)

Q. What is electric current?
Q. 甚麼是電流?

1. The electric current (電流) in a metal wire is a flow of free electrons (自由電子).
1. 在金屬絲裡的電流是一個流動的自由電子。

2. Free electrons are the electrons that escape from an atom and move freely within the conductor.
2. 自由電子是那些從原子逸出並在導電體自由移動的電子。

3. When the conductor is not connected to a dry cell, the free electrons move in different directions.
3. 當導電體不是與乾電池連接，那些自由電子會在不同的方向移動。

4. When the conductor is connected to a dry cell and forms a closed circuit, the free electrons move through the circuit from the negative terminal to the positive terminal of a dry cell. 

4. 當導電體是與乾電池連接和形行閉合電路，自由電子在電路從乾電池的負極移到乾電池的正極。