02. Static

Aim

Explain how some insulators can become electrically charged.

Describe the effect that oppositely charged objects have on each other.

Simple Experiments:

  1. Attach a balloon to the wall

  2. Get a balloon to bend water

  3. Get two balloons to repel each other

  4. Pick up bits of paper using different rods. Now try doing this with metal objects (eg. bar on a stand)

What happens?

draw a diagram of a carbon atom to help you.

Why is this?

what can this rubbing have done, which parts of the atom will be affected?

What materials can do this and why?

Describe the pictures on the right in simple sentences?

Key terms:

charging by friction

transferred

positive/negative charge

electrons

attract/repel

similar/opposite

neutral

Charge (Q) is measured in COULOMBS

1 electron has a charge of

1.6 x 10-19 C

ACTIVITY: Shocking Physics

AtL:

  • Critical-thinking skills Interpret data: Recognise and evaluate propositions

Physics teachers are fond of alarming their students by quoting the voltage (potential difference) carried by the dome of a Van der Graaff generator. However, it is usually pretty safe to touch the dome, or even to allow it to discharge through your body - provided some safety precautions are taken.

The Table below compares the electricity produced when a Van der Graaff generator discharges to that conducted by a standard household mains supply in a county which uses 220 V as a supply.

Compare the values for the Van der Graaff generator and the mains supply.

What makes you think that it might be relatively safe to touch the van der Graaf, but absolutely not safe to touch the contacts of a mains supply socket?

Key concept: Change

Global context: Scientific and technical innovation