A Level Chemistry OCR Practice Exam

Which of the following best describes a covalent bond?

1. A bond formed by a transfer of electrons

2. A bond formed through the sharing of electrons

3. A bond that involves ionic interactions

4. A temporary interaction between atoms

The correct answer is: A bond formed through the sharing of electrons

A covalent bond is best described as a bond formed through the sharing of electrons. In this type of bond, atoms will share one or more pairs of electrons to achieve a full outer electron shell, which typically leads to lower energy and greater stability in the molecule. This sharing allows both atoms involved to experience the benefits of having a full valence shell, effectively holding them together in a stable arrangement. The other options describe different types of bonding or interactions that don’t accurately represent what a covalent bond is. For instance, the transfer of electrons describes ionic bonding, where one atom donates an electron to another, resulting in positive and negative ions. Ionic interactions involve electrostatic forces between charged ions, distinct from the sharing characteristic of covalent bonds. Temporary interactions between atoms might refer to van der Waals forces or hydrogen bonds, which are much weaker than covalent bonds and do not involve the sharing of electrons. Thus, the sharing of electrons captures the essence of what a covalent bond is all about.