(chemistry) The charge assigned to an atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms, regardless of relative electronegativity.

(mathematics, algebra) Any finite or infinite series of the form a_0+a_1x+a_2x²…=∑ᵢa_ixⁱ, where the aᵢ are numbers, but it is understood that no value is assigned to x.

(mathematics) A formalism for a physical theory which is based upon the canonical equations of Hamiltonian dynamics.

plural of canonical formalism

A formalism for a physical theory which is based upon Feynman path integrals.

(organic chemistry) The simplest aldehyde, HCHO, a colourless gas that has many industrial applications; it dissolves in water to give formol (10%) and formalin.

(chemistry) Any of several of the condensation products of the reaction between urea and formaldehyde (and their derivatives) used as a thermosetting material.

(organic chemistry) Any of a range of thermosetting plastics made by reaction of a phenol with formaldehyde

plural of formaldehyde

(organic chemistry) An organic compound with the formula H2C=NOH; the oxime of formaldehyde, used as a reagent in organic synthesis.