## ::Formula

### ::concepts

**Formula**::formulas Chemical::units Volume::example Science::number Atoms::element Mathrm::title

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In science, a **formula** is a concise way of expressing information symbolically as in a mathematical or chemical formula. The informal use of the term * formula* in science refers to the general construct of a relationship between given quantities. The plural of

*formula*can be spelled either as

*formulas*or

*formulae*(from the original Latin).<ref name="oxford">Oxford Dictionaries: formula.</ref>

In mathematics, a formula is an entity constructed using the symbols and formation rules of a given logical language.<ref>{{#invoke:citation/CS1|citation |CitationClass=citation }}</ref> For example, determining the volume of a sphere requires a significant amount of integral calculus or its geometrical analogue, the method of exhaustion;<ref>{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> but, having done this once in terms of some parameter (the radius for example), mathematicians have produced a formula to describe the volume: This particular formula is:

*V*= {{ safesubst:#invoke:Unsubst||$B=4/3}} π

*r*

^{3}

Having obtained this result, and knowing the radius of any sphere in question, we can quickly and easily determine its volume. Note that the volume *V* and the radius *r* are expressed as single letters instead of words or phrases. This convention, while less important in a relatively simple formula, means that mathematicians can more quickly manipulate larger and more complex formulas.<ref>{{#invoke:citation/CS1|citation
|CitationClass=web
}}</ref> Mathematical formulas are often algebraic, closed form, and/or analytical.

In modern chemistry, a chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using a single line of chemical element symbols, numbers, and sometimes other symbols, such as parentheses, brackets, and plus (+) and minus (−) signs.<ref>Atkins, P.W., Overton, T., Rourke, J., Weller, M. and Armstrong, F. *Shriver and Atkins inorganic chemistry* (4th edition) 2006 (Oxford University Press) ISBN 0-19-926463-5</ref> For example, H_{2}O is the chemical formula for water, specifying that each molecule consists of two hydrogen (H) atoms and one oxygen (O) atom. Similarly, O denotes an ozone molecule consisting of three oxygen atoms and having a net negative charge.

In a general context, formulas are applied to provide a mathematical solution for real world problems. Some may be general: **F** = *m***a**, which is one expression of Newton's second law, is applicable to a wide range of physical situations. Other formulas may be specially created to solve a particular problem; for example, using the equation of a sine curve to model the movement of the tides in a bay. In all cases, however, formulas form the basis for calculations.

Expressions are distinct from formulas in that they cannot contain an equals sign (=).<ref>{{#invoke:citation/CS1|citation |CitationClass=citation }}</ref> Whereas formulas are comparable to sentences, expressions are more like phrases.

**Formula sections**

Intro Chemical formulas In computing Formulae with prescribed units See also References External links

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