Reaction: 2Cl(g) ⟶ Cl2(g)

Explanation:
The given reaction represents the conversion of two chlorine atoms (Cl) in the gaseous state into a molecule of chlorine gas (Cl2).

In this reaction, two chlorine atoms combine to form a diatomic molecule of chlorine gas. Each chlorine atom has seven valence electrons, and in order to achieve a stable electron configuration, they both need to gain one electron. By sharing one electron each, they can fulfill the octet rule and form a more stable Cl2 molecule.

The reaction can be represented using Lewis dot structures:
- Cl• + •Cl ⟶ Cl-Cl

Main Points:
- Gaseous chlorine atoms (Cl) combine to form chlorine gas (Cl2).
- Each chlorine atom contributes one electron to the bond formation.
- The reaction involves the sharing of electrons to fulfill the octet rule.
- The resulting Cl2 molecule is more stable compared to individual chlorine atoms.

Summary:
The given reaction represents the combination of gaseous chlorine atoms to form a molecule of chlorine gas. This reaction involves the sharing of one electron each by the chlorine atoms to achieve a stable electron configuration. The resulting Cl2 molecule is more stable than the individual chlorine atoms.