Formula unit Formula unit A formula unit in chemistry is the empirical formula of any ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. It is the lowest whole number ratio of ions represented in an ionic compound. Examples include ionic NaCl and KO and covalent networks such as SiO and C (as diamond or graphite). Ionic compounds do not exist as individual molecules; a formula unit thus indicates the lowest reduced ratio of ions in the compound. A "chemical formula" shows the kinds and numbers of atoms in the smallest representative unit of a substance. In
GESTIS Substance Database results. A mobile version of the GESTIS Substance Database, suitable for smartphones and tablets, is also available. GESTIS Substance Database GESTIS Substance Database is a freely accessible online information system on chemical compounds. It is maintained by the Institut für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung (IFA, Institute for Occupational Safety and Health of the German Social Accident Insurance). Information on occupational medicine and first aid is compiled by Henning Heberer and his team (TOXICHEM, Leuna). The database contains information for the safe handling of hazardous substances and other chemical substances at work: The available information relates to about 9,400 substances.