CH2O is an example of which kind of formula?

CH2O represents the empirical formula of a compound. The empirical formula indicates the simplest whole-number ratio of the atoms of each element in the compound, which for CH2O means that there is one carbon atom, two hydrogen atoms, and one oxygen atom in the smallest repeating unit. This formula provides a simplistic view of the composition of the molecules, without detailing how the atoms are arranged or bonded.

In contrast, the molecular formula would provide the total number of each type of atom in a molecule of the compound, which could be the same as the empirical formula or a multiple of it. The line formula typically provides a simplified, diagrammatic representation of molecular structures without depicting the specific atoms. Lastly, the structural formula illustrates the bonding arrangement between atoms, showing how the atoms are connected in three-dimensional space.