This ontology is intended as an incomplete representation of molecules. It is for tutoring purpose. It is heavily inspired from ChEBI (http://www.ebi.ac.uk/chebi/). As usual, the good stuff comes from them; the errors and over-simplifications are ours. 1.0 2 Helium Sodium HCl Argon Cations are positively charged ions, formed when an atom loses electrons in a reaction. H2O Sulfide Phosphorus A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its nucleus Carbon C6h12O6 Lithium Fluoride Sulfur 1 Hydrogen Phosphide Neon Oxide Oxygen Anions are negatively charged ions, formed when an atom gains electrons in a reaction. Beryllium Chloride H+ Nitrogen An ion is a molecular structure having a net electric charge An ion is an atom or molecule which has lost or gained one or more valence electrons, giving it a positive or negative electrical charge. CH4 Silicon Chlorine Magnesium Aluminium NaOH Fluorine A molecule is an electrically neutral entity consisting of more than one atom. A molecule is a sufficiently stable electrically neutral group of at least two atoms in a definite arrangement held together by very strong chemical bonds . It can also be defined as a unit of two or more atoms held together by covalent bonds. Nitride Boron AlkaliMetal or AlkalineEarthMetal or TransitionMetal or SemiMetal or Actinide or Lanthanide C24H24N4O4 NaCl