Year 9 chemistry recap

Year 9 chemistry recap

1. what are chemicals made of

   • atoms
     • description of atoms have changed over time
     • structure
       • neutrons
     • protons
       • positive charged
       • located in nucleus
       • number of P's defines the ATOMIC NUMBER of an atom - this defines the type of element
     • electrons
       • negatively charged
       • orbit the atom
       • remain in orbit around atom due to attraction for positive charged protons