Ions

• Polyatomic ions

  atoms of more than one element bonded together. Most of these contain the common parts and the charge can be used to work out the oxidation number
• Polyatomic ions (example)

  Ca(NO3)2

  
• Roman numbers

  I = 1

  II = 2

  III = 3

  IV = 4

  V = 5

  IV= 6

  VII = 7

  VIII = 8

  IX= 9

  X = 10
• How to work out polyatomic ions

  you switch the charges arounds

  
• Table of common ions