Aluminium compounds

[bravegirl123]

Although aluminium is a metal, it forms covalent compounds. However I discovered that Al2O3 and AlF3 are ionic compounds. Why is this so and are there any other aluminium compounds that are ionic?

 

[aalmuhannadi]

Although aluminium is a metal, it forms covalent compounds. However I discovered that Al2O3 and AlF3 are ionic compounds. Why is this so and are there any other aluminium compounds that are ionic?

They're ionic because a metal + non-metal always form ionic compounds, isn't that the general rule? If you're unsure about any other aluminium compounds then just see if aluminium is bonded with another metal or a non-metal...

 

[bravegirl123]

They're ionic because a metal + non-metal always form ionic compounds, isn't that the general rule? If you're unsure about any other aluminium compounds then just see if aluminium is bonded with another metal or a non-metal...

yes it is the general rule, but lithium, beryllium and aluminium do not always form ionic compounds, as their atomic size is very small. so the ionization energy becomes really high. instead they form covalent compounds.