formula

formula

1. Maths physics a general relationship, principle, or rule stated, often as an equation, in the form of symbols

2. Chem a representation of molecules, radicals, ions, etc., expressed in the symbols of the atoms of their constituent elements

3. 

a. a prescription for making up a medicine, baby's food, etc.

b. a substance prepared according to such a prescription

4. Motor racing the specific category in which a particular type of car competes, judged according to engine size, weight, and fuel capacity

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

formula

[′fȯr·myə·lə]

(chemistry)

A combination of chemical symbols that expresses a molecule's composition.

A reaction formula showing the interrelationship between reactants and products.

(mathematics)

An equation or rule relating mathematical objects or quantities.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

formula

(1)

In logic, a sequence of symbols representing terms, predicates, connectives and quantifiers which is either true or false.

formula

(language, music)

FORTH Music Language. An extension of FORTH with concurrent note-playing processes. Runs on Macintosh and Atari ST with MIDI output.

["Formula: A Programming Language for Expressive Computer Music", D.P. Anderson et al Computer 24(7):12 (Jul 1991)].

formula

(3)

Preprocessor language for the Acorn Archimedes, allowing inline high-level statements to be entered in an assembly program. Written in nawk.

This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)

formula

(1) An arithmetic expression that solves a problem. For example, (fahrenheit-32)*5/9 is the formula for converting Fahrenheit to Celsius. See formula editor.

(2) In spreadsheets, an algorithm that identifies how the data in a specific number of cells is to be calculated. For example, +C3*D8 means that the contents of cell C3 are to be multiplied by the contents of cell D8 and the results are to be placed in the cell where the formula is located.

Copyright © 1981-2025 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Formula

 

in mathematics, a combination of mathematical symbols that expresses some statement.

Examples of formulas are

It can be seen from these examples that formulas permit rather complicated statements to be written in a compact and convenient form (seeMATHEMATICAL SYMBOLS).

Some formulas—such as (2), (4), and (6) above—express well-defined specific statements and therefore are either true or false. Of these three examples, (2) and (6) are true, and (4) is false.

The sense of other formulas—such as (1), (3), (5), (7), and (8) above—depends on the values of the variables they contain. For example, (1) becomes the true formula 1³ + 2³ < 19 when x = 1, y = 2, and z = 19; on the other hand, if x = 3, y = 4, and z = 5, we have the false formula 3³ + 4³ < 5. Formulas of this type may thus be understood as not being intrinsically true or false. Rather, they become true or false when the variables are replaced by specific objects from some previously chosen domain.

Formulas that are true under any replacement of the variables by objects in some domain are said to be identically true in the domain. For example, formula (5) is identically true in the domain of complex numbers, and formula (8) is identically true in the domain of twice continuously differentiable functions of the arguments x and y. Mathematical laws are written by means of formulas that are true, such as (2) and (6), or identically true in some domain, such as (5) and (8). Moreover, identically true formulas are often understood as assertions with universal validity. For example, the most widely held interpretation of formula (5) considers it to be a shorthand form of the assertion “For any numbers a and b the equality (a + b)² = a² + 2ab + b² holds.”

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Formula

 

in chemistry, a representation of the composition of chemically individual substances by means of chemical symbols and numbers. Chemical formulas generally have the form A_m B_n C_p . . . . A, B, C, . . . represent the atoms of the chemical elements that make up a given substance, while m, n, p, . . . are numbers, usually integers, that indicate how many atoms of each element are contained in a given substance. (In the chemical formulas of nonstoichiometric compounds, the numbers may be fractions.)

To determine the formula of a substance it is necessary to find the quantitative composition of the substance in percent by weight, replace the percent content by weight with ratios between the numbers of atoms, and represent these ratios by integers. For example, an analysis of copper pyrite yields 34.64 percent Cu by weight, 30.42 percent Fe, and 34.94 percent S. Dividing these numbers by the atomic weights of Cu (63.55), Fe (55.85), and S (32.06), we obtain 0.545, 0.545, and 1.090, respectively. These numbers have the ratio 1:1:2, from which we obtain the formula for copper pyrite—CuFeS₂.

The formulas obtained directly from the results of a quantitative analysis are called empirical, or simplest, formulas. In order to establish the molecular formula of a substance, it is necessary to determine the molecular weight of the substance. If this is not possible, only the empirical formula can be used. The empirical formula contains information only about the quantitative composition of a substance. Molecular formulas include additional information about the actual number of atoms of each element per mole of a substance and, if the substance can be converted into a gas, about the weight of one liter of the gas as well.

Structural formulas represent the interatomic bonds in molecules.

REFERENCE

Nekrasov, B. V. Osnovy obshchei khimii, vol. 1, 3rd ed. Moscow, 1973.

S. A. POGODIN

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.