This activity examine some cells and encourages students to work out what happens to produce the voltage that causes the current. Students should gain an understanding of the structure of voltaic cells and of the main factor that determines the voltage produced by the cell.

This item teaches:

• about the convention for representing electrochemical cells
• how the e.m.f. of a cell is calculated
• the factors that determine the voltage produced by an electrochemical cell
• how cells are used to measure electrode potentials