Final answer:
A single covalent bond can be represented as two dots besides the atom symbols, signifying the pair of shared electrons that form the bond.
Step-by-step explanation:
A single covalent bond can be represented as a single line between two atoms or two dots. An example of this is hydrogen gas (H-H) where two hydrogen atoms share their single electrons to form a covalent bond. These shared electrons can be symbolized as a line (H-H) or as two dots (H : H) between the atoms, indicating the shared pair within the molecule.
In a molecule like methane (CH4), a carbon atom with four valence electrons forms single covalent bonds with four hydrogen atoms. The structural formula is often represented by dashes (H-C-H), with each dash indicating a pair of shared electrons forming the single covalent bonds. Similarly, for other molecules, covalent bonds are depicted as lines or pairs of dots between the bonded atoms, with dot and cross diagrams highlighting the shared and lone pairs.