Revision as of 11:17, 5 January 2009

Outcomes

• Pupils understand that atoms have a neutral charge
• Pupils understand that the movement of electrons (through friction)cause insulators to gain electrostatic charge
• Pupils understand that materials can be made to have a temporary charge by induction
• Pupils understand that electrostatic charges can apply forces on one another at a distance

Specification References

• 2.19 identify common materials which are electrical conductors or insulators including metals and plastics
• 2.20 recall that insulating materials can be charged by friction
• 2.21 explain that positive and negative elecrostatic charges are produced on materials by the loss or gain of electrons
• 2.22 recall that there are forces of attraction between unlike charges and forces of repulsion between like charges

Starter

• Structure of an atom recap – get pupils to label each part of the atom (use the small white boards in each classroom)
• Extend the pupils' knowledge of the atom by giving them the scale of the nucleus and atom (order of magnitude - mention Ångström)
• Remind pupils about the idea of a 'balanced' atom (no charge), no. protons = no. electrons

Main Body of Lesson

• Use this worksheet to investigating charging by friction. Pupils use a nanocoulombmeter to investigate charge. To extend this pupils can be asked how many electrons move from the duster to the rod or vice versa, given the charge of an electron.
• Demo (this will be a class practical once we have the equipment) charging by induction - pupils use this worksheet to answer questions about induction.
• The pupils should observe what happens when Rods with different and similar charges interact, this is best done using cradles to hang the rods so that they are free to spin.

Plenary

• Demo charging by friction and induction using rod rubbing: Water stream, bits of paper and Balloon rubbing - pupils use the minature white boards to draw a diagram of where the charges move to; they should be able explain what is happening to the charge.

Additional Information

Resources Required

• Diagram of the atom
• Rods (plastic and metal), cloths, paper bits, yokes hanging by a thread, baloons

Textbook References

• Complete Physics Page 170 + 171 Charging by Friction
• Complete Physics Page 172 Charging by induction

Website References

Skills Addressed

• Observations during experiments

Safety/Hazards

Notes