1. 4.1 Electrical Charges Opposite charges attract Same charge repels.
23 April 2017
4.1 Electrical Charges
Opposite charges attract
Same charge repels.
Insulating materials that lose electrons become positively charged.
Gaining electrons makes an object negative.
Van de Graaff generator
Over 100,000 Volts!
Crackling noises when taking off some clothes is caused by many tiny sparks.

2. Static experiments Rub a polythene (White) rod with a cloth.
Hold the rod near some dry paper.
Hold the rod near a stream of gently running water.
Hold the rod near someone’s hair.
Rub an acetate (clear) rod with a cloth.
Repeat the above experiments. Explain why this happens.

3. Charging by friction + - + - + - + - + - + - + - + - + - + - - - -
Polythene
Uncharged – equal numbers of protons and electrons
After rubbing
cloth
rod
Gains electrons making it __________.
Loses electrons making it __________.
Perspex becomes positively charged after rubbing. Explain why.

4. Van de Graaff Generator
A VdG collects large amounts of charge on the dome.
At the bottom is an acetate roller and at the top a polythene one. How do you think charge reaches the top?

5. AQA Additional Science
21.25%
PSA B2 Biology 45 min exam May %
C2 Chemistry 45 min exam Jun 08 25%
P2 Physics 45 min exam Jun %
Additional ISA 3.75%

6. PSA - Practical Skills Assessment
2 Marks
Work is carried out SAFELY but sometimes lacks a good method.
Apparatus used with help.
4 Marks
Work is SAFE and reasonably organised.
Apparatus used with skill without help.
6 Marks
Work is safe and well organised.
A range of difficult apparatus used with skill.
All measurements taken accurately.
Present data in a suitable table