Which of the following would form the strongest ionic bond?

Question

Al - O

C - F

Na - Mg

H - O

Answer 1

only the top one is a ionic bond. all the rest are impossible or covalent

Answer 2

hahaha, Na-mg

Answer 3

Only Al - O will form an ionic bond. C-F is a polar covalent bond, though its very highly polar, we cant call it an ionic bond. Whereas, in case of Na-Mg, the bond exists very rarely, and is a very weak one(i don't think it exists). And O-H is a covalent bond. So finally i would like to say, that Al - O is the strongest Ionic Bond of these .

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