* Molecular Formula: Describes the exact number and types of atoms in a single molecule. It applies to covalent compounds where atoms share electrons.
* Empirical Formula: Represents the simplest whole-number ratio of atoms in a compound. It doesn't tell us the exact number of atoms in a molecule.
* Ionic Formula: Represents the ratio of ions in an ionic compound.
CaCl₂ is an ionic compound formed from the calcium cation (Ca²⁺) and chloride anion (Cl⁻). The formula shows that for every calcium ion, there are two chloride ions. It's a simple ratio, and therefore it's an empirical formula.
Important Note: You cannot use the term "molecular formula" for ionic compounds like CaCl₂.
