A chlorine atom can typically form one covalent bond.
Explanation
Chlorine (Cl) is a Group 17 element, also known as a halogen. It has 7 valence electrons. To achieve a stable octet (8 valence electrons), like the noble gases, it needs to gain one more electron.
This is achieved through forming a covalent bond, where chlorine shares one of its electrons with another atom, effectively filling its outermost electron shell. Because it only needs one more electron, it typically only forms one covalent bond.
Examples
- Hydrogen Chloride (HCl): Chlorine forms a single covalent bond with hydrogen.
- Chloromethane (CH3Cl): Chlorine forms a single covalent bond with a carbon atom in a methyl group.
Exceptions and Considerations
While chlorine predominantly forms one covalent bond, there are instances where it can participate in more complex bonding scenarios, especially within polyatomic ions or complex molecules. However, these involve different types of interactions and don't strictly adhere to the simple sharing of electrons in a single covalent bond. For example, in perchlorate ($ClO_4^−$), chlorine appears to be bonded to four oxygen atoms, but this is achieved through a combination of covalent and coordinate covalent bonds. For basic bonding considerations, it is important to note that chlorine will only form one simple covalent bond.
