ATOMS

ATOMS

1. NUCLEUS

   • CONTAINS PROTONS AND NEUTRONS
     • PROTONS
       • +
         • RELATIVE CHARGE
       • 1
         • RELATIVE MASS
     • NEUTRONS
       • NEUTRAL 0
         • RELATIVE CHARGE
       • 1
         • RELATIVE MASS
   • MIDDLE OF ATOM
   • IT HAS A POSTIVE CHARGE BECAUSE OF THE PROTONS
   • ALMOST THE WHOLE MASS OF THE ATOM IS CONCENTATED IN THE NUCLEUS

2. ELECTRONS

   • MOVE AROUND THE NUCLEUS IN ENERGY LEVELS CALLED SHELLS
   • -1
     • RELATIVE CHARGE
   • 1/2000
     • RELATIVE MASS

3. IF SOME ELECTRONS ARE ADDED OR REMOVED THE ATOM BECOMES CHARGED AND IS THEN AN ION

4. THE NUMBER OF ELECTRONS EQUALS NUMBER OF PROTONS

5. THE TOP NUMBER IN THE PERIODIC TABLE IS THE MASS NUMBER WHICH S THE TOTAL OF PROTONS AND NEUTRONS

6. THE BOTTOM NUMBER IN THE PERIODIC TABLE IS THE ATOMIC NUMBER WHICH IS THE NUMBER OF PROTONS

7. MOLECULES ARE GROUPS OF ATOMS

   • ONE ELEMENT MOLECULE FOR EXAMPLE HYDROGEN GOES AROUND IN PAIRS
   • WATER IS A 2 ELEMENT MOLECULE
   • HELD TOGETHER BY COBALENT BONDS