The only bonds in a formula unit of caf2 are nonpolar covalent polar covalent ionic metallic

ionic

Explanation:

Ionic bonds exist between Ca and F ions in CaF₂. Ionic bonds are interatomic bonds formed by the transfer of electrons from one atom to the other.

The donor atom here is Ca and it has two valence electrons. Fluorine is the receiving atom with 7 electrons in its outermost shell.

Ca would give one each of its two outermost electrons to the fluorine atoms to complete their octet. Ca ion would now resemble Argon and the flourine atoms would look more like Neon atoms.

This is an ionic bond

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