static electricity (electrostatics)

• ions are formed when atoms lose or gain electrons, resulting in a positive or negative charge
• charges can effect eachother over a distance because the electro-static force is a non-contact force
• What is an electric field?

  The area in which a charged object can effect other charges objects
• A polythene rod becomes negatively charged when rubbed with a dry cloth because it gains electrons from the cloth
• A perspex rod becomes positively charged when rubbed with a dry cloth because it looses electrons
• What are field lines and what do they do?

  They are imaginary lines used to represent the direction and strength of a vector field. They show the path a positive charge would follow in the presence of a force
• what is 'induced charge'?

  When an object charges another object without touching it
• what does the van de graaf machine do?

  generates static electricity by pulling electrons from the Earth, moving them along a belt and stores them in a large sphere
• Describe the forces of attraction and repulsion and give an example?

  Attraction is the force that pulls objects towards each other

  Repulsion is the force that pushes objects away from each other

  e.g. if a negatively charged rod on a string is brought near another negatively charged rod on a string than it will repel but if a positively charged rod on a string is brought near a negatively charged rod on a string than it will attract
• Insulators- plastic, wood, glass and rubber

  Conductors- copper, steel, gold and aluminium