The skeletal formula, sometimes known as the line-angle formula or bond-line formula, is particularly useful for depicting large organic molecules. In this representation, carbon atoms are implied at every vertex or end of a line segment, and hydrogen atoms bonded to carbon are also implied and not drawn. Only atoms other than carbon (like oxygen, nitrogen, etc.) and hydrogens bonded to them are explicitly shown. This shorthand way of drawing eliminates the need to draw every carbon and hydrogen atom, which, for large molecules, would make the diagram cluttered and hard to decipher. Instead, the skeletal formula offers a streamlined and clear visual of the molecule's carbon backbone and functional groups.

Digital models provide several advantages over physical models. Firstly, they can be manipulated easily, allowing for the dynamic visualisation of molecules from various angles and perspectives. They can also simulate molecular motions, such as rotations, vibrations, and conformational changes. Digital models can be integrated with computational chemistry tools, providing insights into molecular properties, potential energy surfaces, and reaction pathways. Furthermore, digital models allow for seamless integration of various molecular representations (space-filling, ball-and-stick, electrostatic potential maps) with a click. While physical models offer tangible, hands-on experience, digital models provide versatility, dynamism, and in-depth molecular insights, making them invaluable in modern chemistry education.

While molecular formulas give the exact number and type of atoms in a compound, they don't provide any information about how these atoms are connected or arranged. Structural formulas, on the other hand, show the specific arrangement of atoms in the compound, illustrating how each atom is bonded to the others. They explicitly depict single, double, or triple bonds and the connectivity of different functional groups. For example, both ethanol (CH₃CH₂OH) and dimethyl ether (CH₃OCH₃) have the same molecular formula, C₂H₆O, but different structural formulas. This difference in structure results in distinct properties and behaviours. Hence, structural formulas offer a more comprehensive understanding of a molecule's architecture and potential reactivity.

Carbon's ability to form double and triple bonds is crucial in organic chemistry as it introduces variability in molecular structure, leading to compounds with different properties. Double and triple bonds arise from the overlap of atomic orbitals, resulting in π and σ bonds. Double bonds consist of one σ and one π bond, while triple bonds consist of one σ and two π bonds. These multiple bonds affect the compound's reactivity, physical properties, and molecular geometry. For instance, alkenes, with carbon-carbon double bonds, are more reactive than alkanes, with single bonds, due to the presence of the π bond that is more exposed and easily broken.

Carbon is considered tetravalent because it has four valence electrons in its outer shell. Looking at its electron configuration, 1s² 2s² 2p², carbon has two electrons in the 2s orbital and two in the 2p orbitals. To achieve a stable electron configuration resembling that of a noble gas, carbon needs four more electrons. By sharing its four valence electrons with other atoms in covalent bonds, carbon effectively achieves this full outer shell configuration. This tetravalency allows carbon to form a wide variety of molecules and compounds by bonding with up to four other atoms simultaneously.