International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

What is the nature of a covalent bond?

1. Bonding through the transfer of electrons

2. Attraction between oppositely charged ions

3. Sharing of a pair of electrons between two nuclei

4. Weak interactions between individual atoms

The correct answer is: Sharing of a pair of electrons between two nuclei

Covalent bonds are characterized by the sharing of pairs of electrons between two atoms, typically nonmetals. This sharing allows each atom to attain a stable electron configuration, often resembling that of the nearest noble gas. In a covalent bond, the involved atoms form a strong connection, as the shared electrons move in the space between the nuclei of both atoms, thus holding them together due to the mutual attraction they exert on the shared electrons. This shared nature distinguishes covalent bonds from other types of bonding, such as ionic bonding, which involves the transfer of electrons leading to the formation of charged ions. The description of a covalent bond highlights its strength and stability, making it a fundamental feature in the formation of molecules in chemistry.