Final answer:
The empirical formula is the simplest whole-number ratio of the elements in a compound, different from the molecular formula, which shows the exact number of each atom. The chemical formula includes subscripts for multiple atoms and parentheses for polyatomic ions, but none of these indicate atom arrangement.
Step-by-step explanation:
Understanding the Empirical Formula
An empirical formula represents the simplest whole-number ratio of elements in a compound. It is not the same as the molecular formula, which shows the exact number of atoms of each element in a molecule. For instance, while the molecular formula for glucose is C6H12O6, reflecting its actual atomic makeup, the empirical formula for glucose is CH2O. This means that for every carbon atom in glucose, there are two hydrogen atoms and one oxygen atom in a simplified ratio.
A molecular formula provides more specific information, delineating the actual number of atoms present in a single molecule of the compound. However, it does not show the arrangement of these atoms. When chemists are determining the composition of an unknown compound, the empirical formula is often the first step. After establishing the empirical formula, they can then deduce the molecular formula.
Lastly, the chemical formula for a substance gives an insight into the elements present and their relative quantities. When a chemical formula includes a subscript, it indicates multiple atoms of that element. Polyatomic ions are also part of chemical formulas and are enclosed in parentheses when present in multiples.