formula /for·mu·la/ (for´mu-lah) pl. formulas, for´mulae [L.] an expression, using numbers or symbols, of the composition of, or of directions for preparing, a compound, such as a medicine, or of a procedure to follow to obtain a desired result, or of a single concept.
chemical formula a combination of symbols used to express the chemical composition of a substance.
dental formula an expression in symbols of the number and arrangement of teeth in the jaws. Letters represent the various types of teeth: I, incisor; C, canine; P, premolar; M, molar. Each letter is followed by a horizontal line. Numbers above the line represent maxillary teeth; those below, mandibular teeth. The human dental formula is I22C11M22= 10 (one side only) for deciduous teeth, and I22C11P22M33= 16 (one side only) for permanent teeth.
empirical formula a chemical formula which expresses the proportions of the elements present in a substance.
molecular formula a chemical formula expressing the number of atoms of each element present in a molecule of a substance, without indicating how they are linked.
spatial formula , stereochemical formula a chemical formula giving the number of atoms of each element present in a molecule of a substance, which atom is linked to which, the type of linkages involved, and the relative positions of the atoms in space.
structural formula a chemical formula showing the number of atoms of each element in a molecule, their spatial arrangement, and their linkage to each other. 
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Structural formulas for ethanol.
vertebral formula an expression of the number of vertebrae in each region of the spinal column; the human vertebral formula is C7 T12 L5 S5 Cd4 = 33.
struc·tur·al formula (str k ch r-l)n. A chemical formula that shows the number and kinds of atoms in a molecule and how the atoms and bonds in the molecule are arranged. |
formula
pl. formulae, formulas [L.] an expression, using numbers or symbols, of the composition of, or of directions for preparing, a compound, such as a medicine, or of a procedure to follow to obtain a desired result, or of a single concept.
chemical formula
a combination of symbols used to express the chemical components of a substance.
dental formula
see dental formula.
empirical formula
a chemical formula that expresses the proportions of the elements present in a substance.
gait formula
sets out the times that the feet are individually in contact with the ground while the animal is moving.
molecular formula
a chemical formula expressing the number of atoms of each element present in a substance, without indicating how they are linked.
spatial formula, stereochemical formula
a chemical formula giving the numbers of atoms of each element present in a molecule of a substance, which atom is linked to which, the types of linkages involved, and the relative positions of the atoms in space.
structural formula
a chemical formula showing the spatial arrangement of the atoms and the linkage of every atom.
vertebral formula
sets out the number of vertebrae in each of the sections of the spinal column.
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