Respuesta :

if you look at AIF3 and AICI3, the F ion is smaller than a CI ion. that’s why AICI3 will make a covalent bond while AIF3 will make a ionic bond. explanation: AICI3 doesn’t have a complete transfer of electrons between the metal and the non-metal.
MercilessSpark

Simple

Look at Electronic configuration of Al

  • [Ne]3s²3p¹

It has valency as 3

So it can make 3 bonds

  • Chlorine has well known valency 1

So

Aluminium does bonding with 3 chlorine atoms

There is another reason

That's electronegativity

  • Chlorine is most electronegative element
  • Aluminium has low electronegativity

As difference in electronegativity is higher they forms ionic bond