Structure

 

 

How to differentiate:

 

Metal and Non-Metals

  • In the Periodic Table, metals are found on the left, non-metals are found on the right.
  • Refer to dividing line in Periodic Table.

Covalent and Ionic Compounds

  • Basis: Electronegativity difference

Large Ionic
Small Covalent

  • The following generalisation is applicable:

Metal + Non-Metal Ionic
Non-Metal + Non-Metal Covalent

 

Notable Exceptions:

  • AlCl3, AlBr3, AlI3
  • BeX2

Simple and Giant Molecular Structures

  • Memorise the common giant molecules (diamond, graphite, SiO2)
  • Can safely regard the rest of the covalent compounds as having simple structures.