What is the valency of fluorine in calcium fluoride, CaF₂?

The valency of fluorine in CaF₂ is 1.

• Fluorine (F) belongs to Group 17 (halogens) and has 7 valence electrons.
• Needs 1 electron to complete its octet — forms one bond → valency of 1.
• In CaF₂: Calcium has valency 2, so bonds with two fluorine atoms (each valency 1).

Check: Ca²⁺ + 2F⁻ = CaF₂. Charges balance perfectly.

Fluorine has a valency of 1 in CaF₂, combining with divalent calcium to form a neutral, stable compound.