[Inconspicuous]

So, I think we all know that the covalent character of a bond made between two atoms can be estimated by finding the difference in electronegativity between them, but how does this apply to covalent oxyanions? Also, is there a better unit in place of measuring the covalent character of a bond, or a unit of measurement that is related to the covalent character of a bond?

[Inconspicuous]

To give some more information, I was referring to the ionic bond that is present between a metal ion and an oxyanion. For example, magnesium sulfate. Can we just use the difference in electronegativity between magnesium and oxygen to determine the covalent character of the bond between the magnesium ion and the sulfate ion?

[Orcio_87]

For example, magnesium sulfate. Can we just use the difference in electronegativity between magnesium and oxygen to determine the covalent character of the bond between the magnesium ion and the sulfate ion?

You will need to use the difference between Mg and SO₄.