Elements definition, a component or constituent of a whole or one of the parts into which a whole may be resolved by analysis: Bricks and mortar are elements of every. A chemical element or element is a species of atoms having the same number of protons in their atomic nuclei (i.e. the same atomic number, Z). There are 118 elements. Interactive periodic table. Clicking on an element brings up a list of general properties and data, and information on its discovery, history, uses, geologic. Define element: chemistry : one of the basic substances that are made of atoms of only one kind and that cannot be separated… — element in a sentence. el·e·ment (ĕl′ə-mənt) n. 1. A fundamental, essential, or irreducible constituent of a composite entity. 2. elements The basic assumptions or principles of a. Provides information on the 109 named elements plus elements 110 - 112. In mathematics, an element, or member, of a set is any one of the distinct objects that make up that set. What are elements? The chemical elements are central to the study of chemistry. Here is the element definition and examples. An element is composed of atoms that have the same atomic number, that is, each atom has the same number of protons in its nucleus as all other atoms of that element. elements The basic assumptions or principles of a subject. Element - definition of element by The Free Dictionary. .