atom, fraction, member, section, component, fragment, particle, segment, constituent, ingredient, piece, share, division, instalment, portion, subdivision. element,
_Part_, a substance, quantity, or amount that is the result of the division of something greater, is the general word, including all the others of this group. A _fragment_ is the result of breaking, rending, or disruption of some kind, while a _piece_ may be smoothly or evenly separated and have a certain completeness in itself. A _piece_ is often taken for a sample; a _fragment_ scarcely would be. _Division_ and _fraction_ are always regarded as in connection with the total; _divisions_ may be equal or unequal; a _fraction_ is one of several equal _parts_ into which the whole is supposed to be divided. A _portion_ is a _part_ viewed with reference to some one who is to receive it or some special purpose to which it is to be applied; in a restaurant one _portion_ (_i. e._, the amount designed for one person) is sometimes, by special order, served to two; a _share_ is a _part_ to which one has or may acquire a right in connection with others; an _instalment_ is one of a series of proportionate payments that are to be continued till the entire claim is discharged; a _particle_ is an exceedingly small _part_. A _component_, _constituent_, _ingredient_, or _element_ is a _part_ of some compound or mixture; an _element_ is necessary to the existence, as a _component_ or _constituent_ is necessary to the completeness of that which it helps to compose; an _ingredient_ may be foreign or accidental. A _subdivision_ is a _division_ of a _division_. We speak of a _segment_ of a circle. Compare PARTICLE; PORTION.
atom, grain, mite, scrap, whit. corpuscle, iota, molecule, shred, element, jot, scintilla, tittle,
A _particle_ is a very small part of any material substance; as, a _particle_ of sand or of dust; it is a general term, not accurately determinate in meaning. _Atom_ (Gr. _a-_ privative, not, and _temno_, cut) etymologically signifies that which can not be cut or divided, and is the smallest conceivable _particle_ of matter, regarded as absolutely homogeneous and as having but one set of properties; _atoms_ are the ultimate _particles_ of matter. A _molecule_ is made up of _atoms_, and is regarded as separable into its constituent parts; as used by physicists, a _molecule_ is the smallest conceivable part which retains all the characteristics of the substance; thus, a _molecule_ of water is made up of two _atoms_ of hydrogen and one _atom_ of oxygen. _Element_ in chemistry denotes, without reference to quantity, a substance regarded as simple, _i. e._, one incapable of being resolved by any known process into simpler substances; the _element_ gold may be represented by an ingot or by a _particle_ of gold-dust. In popular language, an _element_ is any essential constituent; the ancients believed that the universe was made up of the four _elements_, earth, air, fire, and water; a storm is spoken of as a manifestation of the fury of the _elements_. We speak of _corpuscles_ of blood. Compare PART.