Give reasons:
When `Cl_2` reacts with excess of `F_2, CIF_3` is formed and not `FCl_3`.

Explanation

To understand why ClF3 is formed instead of FCl3 when Cl2 reacts with excess F2, we need to analyze the electronic configuration and bonding capabilities of chlorine (Cl) and fluorine (F).

### Step-by-step Solution:

1. **Understanding the Reactants**:
- Chlorine (Cl2) is a diatomic molecule consisting of two chlorine atoms.
- Fluorine (F2) is also a diatomic molecule consisting of two fluorine atoms.

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