Here's why:

* Single Displacement Reactions: In these reactions, a more reactive element displaces a less reactive element from a compound.

* The Reaction: In your example, fluorine (F2) is more reactive than chlorine (Cl2). Fluorine displaces chlorine from calcium chloride (CaCl2) to form calcium fluoride (CaF2) and elemental chlorine (Cl2).

The General Pattern of a Single Displacement Reaction:

A + BC → AC + B

Where:

* A is the more reactive element

* B is the less reactive element

* BC is the compound

In your case:

* A = F2 (fluorine)

* B = Cl2 (chlorine)

* BC = CaCl2 (calcium chloride)

The Balanced Equation:

CaCl2 + F2 → CaF2 + Cl2