Outcomes

Pupils can identify the coulomb as the unit of charge
Pupils can identify the Ampere as the unit of current and that it is a SI Base Unit
Pupils can use the equation Q = It and define current as the rate of flow of charge

Specification References

2.16 understand that current is the rate of flow of charge

2.17 recall and use the relationship between charge, current and time : charge = current × time, Q = I × t

2.18 recall that electric current in solid metallic conductors is a flow of negatively charged electrons

Shuttling ball demonstration. The pupils (using the mini white boards) are asked to explain why the ball shuttles- testing their understanding of the different types of charge, induced charge and interactions between different polarities of charge. This leads to the discussion of the movement of charge being current and what factors affect the rate at which it is being moved.

The pupils observe a demonstration in which a nanocoulombmeter is charged with a constant current (5nA works well). The current is controlled using a potential divider. To record the data and draw a circuit diagram the following worksheet can be used. The charge is measured every 5 seconds for 40 seconds and a graph of charge against time is plotted. This can (if time permits) be repeated using a larger current (10nA works well) to charge the nanocoulombmeter. Plot grpahs and calculate the gradient of these lines (taking care with units). A conclusion should be draw about their findings.
Go through the structure of metals breifly (sea of free electrons) and how the current is the rate of flow of electrons around a circuit. Pupils need to know that current in a ciruit is the "flow of [free] negative electrons from the negative terminal to the positive". This is sometimes referred to as "the nature of current in a metal conductor".

Practical equipment for the shuttling ball demonstration and charging the nanocoulombmeter.