Why halogens are very reactive?

Explanation

### Step-by-Step Solution:

1. **Understanding Halogens**:
- Halogens are a group of elements in Group 17 of the periodic table, which include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). They typically exist as diatomic molecules (e.g., F2, Cl2).

2. **Bond Dissociation Energy**:
- Halogens have low bond dissociation energies. This means that the bonds holding the two atoms together in their diatomic form are relatively weak. For example, the bond in F2 is easier to break than in many other molecules.
- Because these bonds are weak, halogens can easily react with other elements, breaking their bonds and forming new compounds.
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