Which of the following best describes the information provided by a molecular formula?

• A. It shows the exact number of each type of atom in a single molecule of a compound.
• B. It shows the physical properties of a compound.
• C. It shows the simplest whole-number ratio of atoms in a compound.
• D. It shows the arrangement of atoms within a molecule.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand what a molecular formula represents. A molecular formula provides the exact number of each type of atom present in a single molecule of a compound.
2. Step 2: Differentiate the molecular formula from other types of chemical formulas. For example, an empirical formula shows the simplest whole-number ratio of atoms, not the exact count.
3. Step 3: Recognize that a molecular formula does not provide information about the physical properties of a compound; these are determined by other factors such as molecular structure and intermolecular forces.
4. Step 4: Note that the molecular formula does not show the arrangement or connectivity of atoms within the molecule; that information is given by structural formulas or Lewis structures.
5. Step 5: Conclude that the best description of the molecular formula is that it shows the exact number of each type of atom in a single molecule of a compound.