Step 1: Understanding the Concept:
Isomorphism is a phenomenon observed in solid-state chemistry where different chemical substances crystallize in the same geometric form.
Step 3: Detailed Explanation:
In isomorphous substances, the atoms are arranged in the same way, and the ratio of atoms in their chemical formulas is identical.
For example, \(NaF\) and \(MgO\) are isomorphous because they both have a 1:1 atomic ratio and crystallize in the same cubic structure.
Similarly, \(K_2SO_4\) and \(K_2SeO_4\) are isomorphous as they share the same crystal lattice arrangement.
Step 4: Final Answer:
Isomorphism is defined as the property of two or more different substances to have the same crystal structure and similar chemical formulas.