Ionic bonding in CaF₂

Steps:

• Calcium (group 2) has two outer electrons; each fluorine (group 17) needs one to complete octet.
• In CaF₂, calcium loses two electrons to form Ca²⁺, each fluorine gains one to form F⁻.
• The diagram must show calcium with empty outer shell and two fluorines with full octets.
• Verify by checking electron transfer and charge balance.

Why C is correct:

• Depicts Ca donating one electron to each of two F atoms, achieving noble gas configurations per ionic bonding rules.

Why the others are wrong:

• A shows covalent sharing, not ionic transfer.
• B shows only one F atom receiving electrons, ignoring CaF₂ formula.
• D shows Ca retaining electrons, violating group 2 valency.

Final answer: C