* Ionic compounds do not form molecules. They form crystal lattices where positive and negative ions are held together by electrostatic attraction in a fixed ratio.
* The formula represents the simplest whole-number ratio of ions in the compound. It doesn't show the actual arrangement or number of ions in the crystal structure.
Example:
* NaCl (sodium chloride): The formula shows one sodium ion (Na+) for every chloride ion (Cl-). It doesn't tell you how many sodium or chloride ions are present in a particular crystal.
In contrast, covalent compounds form molecules, and their chemical formulas represent the actual number and types of atoms in a single molecule.
Example:
* H2O (water): The formula shows that a water molecule contains two hydrogen atoms and one oxygen atom.
