Which of the following is an example of a molecular formula?

The correct answer is indeed one of the examples of a molecular formula, as a molecular formula specifies the number and types of atoms in a molecule. In this case, the molecular formula CH4 indicates that each molecule consists of one carbon atom (C) and four hydrogen atoms (H).

This formula is representative of methane, a common hydrocarbon, and illustrates how a molecular formula provides insight into the composition of a substance on a molecular level. The molecular formula conveys not just the elements involved, but also showcases the precise number of each type of atom present in the molecule.

By contrast, while H2O and C6H12O6 are also molecular formulas, the answer specified here focuses on CH4, which is a simpler example. On the other hand, NaCl represents an ionic compound rather than a molecular compound. Ionic compounds are composed of charged ions rather than discrete molecules, which is why it does not fit the definition of a molecular formula.