What does a molecular formula show?

What does a molecular formula show?

• A. The number of atoms from each element
• B. The bonds between atoms
• C. The three-dimensional arrangement
• D. The charge on the molecule

Answer: (A)

A molecular formula shows the exact number of atoms of each element in one molecule. For example, glucose has C6H12O6, so there are six carbons, twelve hydrogens, and six oxygens in one molecule. It tells you the composition, not how the atoms are arranged or bonded together, which would require a structural formula. It also doesn’t reveal the three-dimensional shape or arrangement, which needs models or space-filling representations, nor does it display any overall charge (ions are shown with a charge on the ion, not just by the molecular formula). If you wanted the simplest whole-number ratio of elements, you’d look at the empirical formula, but the molecular formula gives the actual counts in a molecule.

A molecular formula shows the exact number of atoms of each element in one molecule. For example, glucose has C6H12O6, so there are six carbons, twelve hydrogens, and six oxygens in one molecule. It tells you the composition, not how the atoms are arranged or bonded together, which would require a structural formula. It also doesn’t reveal the three-dimensional shape or arrangement, which needs models or space-filling representations, nor does it display any overall charge (ions are shown with a charge on the ion, not just by the molecular formula). If you wanted the simplest whole-number ratio of elements, you’d look at the empirical formula, but the molecular formula gives the actual counts in a molecule.