Final answer:
The molecular formula for hydrogen cyanide (HCN) indicates that there is one hydrogen atom, one carbon atom, and one nitrogen atom in each molecule.
Step-by-step explanation:
The molecular formula for a compound provides information about the types and quantities of atoms present in the molecule. In the case of hydrogen cyanide (HCN), the formula indicates that there is one hydrogen atom (H), one carbon atom (C), and one nitrogen atom (N) in each molecule of hydrogen cyanide.
The subscript next to each element symbol represents the number of atoms of that element in the molecule. For example, in HCN, the subscript 1 next to H indicates that there is one hydrogen atom, whereas the absence of a subscript next to C and N indicates that there is only one atom of each.
The molecular formula does not provide information about the arrangement or connectivity of the atoms in the molecule, which is shown by the structural formula. The molecular formula is a concise representation of the elemental composition of the compound.