What Determines Atomic Bonding: Ionic, Covalent, or Polar Covalent?

[kasse]

Is there any rule that I can use to determine if an atom will consist of ionic bondings, covalent bondings or polar covalent bondings? I'm thinking of difference in electronegativity on the Pauling scale.

 

[Kushal]

you mean a compound?!

the electronegativity difference should be more than 1.7 for the compound to be ionic.

 

[Kushal]

also, when there is an ion of high charge density(e.g. in AlCl3), covalency may occur.