Year 9 Physics Electricity 

Static Electricity

• a charged particle is a particle that has an electric charge that is either a negative, positive, or neutral charge
  • for example, a proton, neutron, or electron
• a unit of elementary electrical charge is a coulomb

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Structure of the Atom

• nucleus has:
  • protons which are positively charged
  • neutrons which have no charge but contribute to the mass of the nucleus
• protons and neutrons have a very similar mass/weight
  • 1800x times heavier than electrons
• electrons spin around in space surrounding the nucleus
• the overall charge of the atom is neutral as protons and electrons cancel out each others charge

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Valence Shells

• ions are most stable when their outer (valence) shell is full of electrons
• but, atoms without valence shells:
  • gain electrons to become negative and become anions
  • lose electrons to become positive and become cations
• cations - positive ions
• anions - negative ions

things in the universe tend to go to their lowest energy level - this is why atoms try to have less unstable shells, so thats why ions are formed to try and stabilise their valence shells

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Electricity

• electricity is energy that is being transported between points
  • electricity flows - it is the flow of negative charge, electrons
• it is transported so that it can be transformed into other types of energy

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Conductors

• when electricity flows through a material, it is being conducted
• conductors are materials that electricity can flow through well
• for example, water, metals like copper
• in a metal, there are lots of atoms
  • if an electro breaks free from one atom it is attracted to the other atoms, where it will bind
  • as a result, electricity flows through

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