Batteries are made up of two separate compartments called half cells. The electrons are forced from one compartment to another. The electrons travel through the wire as the pass from one compartment to the other. As electrons leave one compartment and go to the other charge builds up in each compartment and stops the electrons moving. A salt bridge is used to minimise the build up of charge and keep the electrons flowing.

 

View the animation of the Elecrochemical cell .

After viewing the animations answer the following questions.
1) What charge builds up in the half cell where the electrons go to?
2) What charge builds up in the half cell where the electrons come from?
3) What charge particles, from the salt bridge, flow into the half cell where the electron go to?
4) What charge particles, from the salt bridge, flow into the half cell where the electron come from?
5) Knowing that similar charges repel each other while opposite charge attract each other suggest why the flow of electrons stops as the charge builds up in each half cell.
*Electrons are negatively charge