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

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

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

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

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