static electricity

• What is the term used for the build-up of charge on insulating materials?

  Static electricity
• What causes the build-up of static electricity on insulating materials?

  Friction causes electrons to transfer from one material to another
• What happens to electrons when materials are rubbed together?

  Electrons are transferred from one material to another
• How do electrons behave in conducting materials like metals?

  Electrons are able to move freely
• What happens to electrons in insulating materials?

  Electrons cannot flow freely
• What determines how electrons are transferred between materials?

  The specific materials involved determine the transfer of electrons
• Which type of electrons are transferred during the build-up of static electricity?

  Only negative electrons are transferred
• What happens to objects that keep gaining negative electrons?

  The size of the charge increases
• What develops between charged materials when there is a build-up of charge?

  A potential difference (p.d) develops
• What occurs if the potential difference is large enough?

  Electrons jump across to the earth
• What is the process of static electricity build-up on insulating materials?

  • Rubbing materials together causes friction
  • Electrons transfer from one material to another
  • Only negative electrons are involved
  • Charge increases on the material gaining electrons
  • A potential difference develops if the charge is large enough
  • Electrons may jump to the earth
• all charged particles have an electrical field
• field lines always point from positive to negative
• Electric fields are strongest when close to the charged particle, and get weaker further away from the charged particle.
• A strongly charged object can ionise the air, which means the air:

  • loses some of its electrons
  • conducts electricity