What's the difference between i.e. and e.g.?
c.1300, "earth, air, fire, or water," from Old French element (10c.), from Latin elementem "rudiment, first principle, matter in its most basic form" (translating Greek stoikheion), origin unknown. Meaning "simplest component of a complex substance" is late 14c. Modern sense in chemistry is from 1813. Elements "atmospheric force" is 1550s.
element el·e·ment (ěl'ə-mənt)
A substance that cannot be reduced to simpler substances by normal chemical means and that is composed of atoms having an identical number of protons in each nucleus.
A fundamental, essential, or irreducible constituent of a composite entity.
Our Living Language : When Russian chemist Dmitri Mendeleev devised the Periodic Table in 1869, there were 63 known elements. Mendeleev classified the known elements by atomic weight, and arranged a table listing them with vertical rows corresponding to shared chemical characteristics. Gaps in the table suggested the possibility of elements not yet discovered, and indeed elements were later discovered, or in some cases, artificially created, that filled the gaps and had the expected chemical properties. The striking correlation between the atomic weight of an element and its chemical properties was later explained by quantum mechanical theories of the atom. The weight of an atom of any given element depends on the number of protons (and neutrons) in its nucleus, but the number of protons also determines the number and arrangement of electrons that can orbit the nucleus, and it is these outer shells of electrons that largely determine the element's chemical properties. Currently, 115 distinct elements are known.
In chemistry, any material (such as carbon, hydrogen, iron, or oxygen) that cannot be broken down into more fundamental substances. Each chemical element has a specific type of atom, and chemical compounds are created when atoms of different elements are bound together into molecules. There are 119 chemical elements whose discovery has been claimed; 92 occur in nature, and the rest have been produced in laboratories.