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A chemical formula that indicates the relative proportions of the elements in a molecule rather than the actual number of atoms of the elements.
1. (Chemistry) a chemical formula indicating the proportion of each element present in a molecule: C6H12O6 is the molecular formula of sucrose whereas CH2O is its empirical formula. Compare molecular formula, structural formula
2. (General Physics) a formula or expression obtained from experimental data rather than theory
a chemical formula showing the elements of a compound and their relative proportions, as (CH2O)n or H2O.