YEAR 9 CHEMISTRY RECAP

YEAR 9 CHEMISTRY RECAP

1. WHAT ARE CHEMICALS MADE OF?

   • ATOMS
     • DESCRIPTIONS OF ATOMS HAVE CHANGED OVER TIME
     • SCRUCTURE
       • NEUTRONS
         • MASS OF APPROX. 1 AMU
       • PROTONS
         • POSITIVLEY CHARGED
         • LOCATED IN THE NUCLEUS
         • MASS OF APPROX 1. AMU
       • ELECTRONS
         • NEGATIVLEY CHARGED
         • ORBIT THE ATOM
         • REMAIN IN ORBIT AROUND ATOM DUE TO ATTRACTION FOR POSITIVELY CHARGED PROTONS
         • CHANGING THE OF E- GIVES THE ATOM A CHARGE - CALLED AN ION
         • VERY LOW MASS