Final answer:
A single covalent bond represents the sharing of two electrons between two atoms. Examples include the hydrogen molecule (H-H), where two hydrogen atoms share a pair of electrons to form this type of bond.
Step-by-step explanation:
A single covalent bond represents the sharing of two electrons, with one electron contributed by each of the two atoms involved in the bond. An example of a single covalent bond is in a molecule of hydrogen gas (H-H), where the two hydrogen atoms share a pair of electrons to achieve a stable electronic arrangement. This sharing forms a strong chemical bond between the atoms, which is essential for the molecule's stability.
Molecules can also form double or triple covalent bonds, where additional pairs of electrons are shared. For instance, a double covalent bond involves the sharing of four electrons—two from each atom, while a triple covalent bond involves the sharing of six electrons, with three from each atom. Each of these bonds means more electrons are shared between the same two atoms.