Concept:Isomorphism occurs when two or more distinct chemical compounds crystallize in the exact same geometric crystal structure.
Formula:Not applicable.
Solution:- Sodium nitrate (\( \text{NaNO}_3 \)) and Calcium carbonate (\( \text{CaCO}_3 \)) are two entirely different chemical compounds.
- However, due to similar ionic radii ratios and identical atomic ratios (1:1:3), they arrange themselves into identical trigonal crystal lattices.
- Compounds exhibiting this structural mimicry are termed "Isomorphs."
Why other options are incorrect:Polymorphs refer to a single substance existing in multiple structural forms. Allotropes refer to elements (like Carbon as diamond or graphite). Isomers are molecules with the same chemical formula but different structural connectivity.
(Note: The original source listed 'Isomorphs' as Option E, it has been mapped to Option D here for standard JSON compliance.)
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