[monarchus]

i would like to ask that is covalent bonding formed depends on the polarizing power of an atom? or it is depends on the electronegativity of an atom?

and below is an extraction from my inorganic reference book:

"Generally, electronegativity and oxidising ability decrease on decending Group 17. This result in an increase of covalent character in the ionic compounds. This explain why aluminium flouride is ionic whereas aluminium chloride is covalent."

why it is electronegativity and oxidising ability decrease on decending Group 17. This result in an increase of covalent character in the ionic compounds?

wasn't it is the decrease in electronegativity of an atom, the weaker it pulls the electron density from another atom, the less the electrons overlaps, and hence less covalent it is?

thank you for your help.

[Mitch]

wasn't it is the decrease in electronegativity of an atom, the weaker it pulls the electron density from another atom, the less the electrons overlaps, and hence less covalent it is?

As you go down a group, the atom's electron clouds become more disperse and will overlap better.

[monarchus]

As you go down a group, the atom's electron clouds become more disperse and will overlap better.

well, i think i know the reason already. thank you.

[Mitch]

hmm?