''Quantities, Units and Symbols in Physical Chemistry'', also known as the ''Green Book'', is a compilation of terms and symbols widely used in the field of

physical chemistry Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mech ...

. It also includes a table of

physical constant A physical constant, sometimes fundamental physical constant or universal constant, is a physical quantity that cannot be explained by a theory and therefore must be measured experimentally. It is distinct from a mathematical constant, which has a ...

s, tables listing the properties of

elementary particle In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. The Standard Model presently recognizes seventeen distinct particles—twelve fermions and five bosons. As a c ...

chemical element A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its ...

s, and

nuclide Nuclides (or nucleides, from nucleus, also known as nuclear species) are a class of atoms characterized by their number of protons, ''Z'', their number of neutrons, ''N'', and their nuclear energy state. The word ''nuclide'' was coined by the A ...

s, and information about conversion factors that are commonly used in physical chemistry. The ''Green Book'' is published by the

International Union of Pure and Applied Chemistry The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...

(IUPAC) and is based on published, citeable sources. Information in the ''Green Book'' is synthesized from recommendations made by IUPAC, the

International Union of Pure and Applied Physics The International Union of Pure and Applied Physics (IUPAP; ) is an international non-governmental organization whose mission is to assist in the worldwide development of physics, to foster international cooperation in physics, and to help in the ...

(IUPAP) and the

International Organization for Standardization The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries. M ...

(ISO), including recommendations listed in the IUPAP Red Book ''Symbols, Units, Nomenclature and Fundamental Constants in Physics'' and in the

ISO 31 ISO 31 (Physical quantity, Quantities and Physical unit, units, International Organization for Standardization, 1992) is a superseded international standard concerning physical quantities, units of measurement, their interrelationships and their pr ...

standards.

History, list of editions, and translations to non-English languages

The third edition of the ''Green Book'' () was first published by IUPAC in 2007. A second printing of the third edition was released in 2008; this printing made several minor revisions to the 2007 text. A third printing of the third edition was released in 2011. The text of the third printing is identical to that of the second printing. A Japanese translation of the third edition of the ''Green Book'' () was published in 2009. A French translation of the third edition of the ''Green Book'' () was published in 2012.
Portuguese translation
(Brazilian Portuguese and European Portuguese) of the third edition of the ''Green Book'' () was published in 2018, with updated values of the physical constants and atomic weights; it is referred to as the "Livro Verde". A concise four-page summary of the most important material in the ''Green Book'' was published in the July–August 2011 issue of ''Chemistry International'', the IUPAC news magazine. The second edition of the ''Green Book'' () was first published in 1993. It was reprinted in 1995, 1996, and 1998. The ''Green Book'' is a direct successor of the ''Manual of Symbols and Terminology for Physicochemical Quantities and Units'', originally prepared for publication on behalf of IUPAC's Physical Chemistry Division by M. L. McGlashen in 1969. A full history of the Green Book's various editions is provided in the historical introduction to the third edition. The second edition and the third edition (second printing) of the ''Green Book'' have both been made available online as PDF files; the PDF version of the third edition is fully searchable. The four-page concise summary is also available online as a PDF file. External Links (below).

Handy content

In addition to the obvious data on quantities, units and symbols, the compilation contains some less obvious but very useful information on related topics.

Quantity calculus

Unit conversion is a notorious source of errors. Many people apply individual rules, e.g. "to obtain length in centimeters multiply the length in inches by 2.54", but combining several such conversions is laborious and prone to mistakes. A better way is to use the factor-label method, which is closely related to dimensional analysis, and

quantity calculus Quantity calculus is the formal method for describing the mathematical relations between ''abstract'' physical quantities. Its roots can be traced to Fourier's concept of dimensional analysis (1822). The basic axiom of quantity calculus is Maxw ...

explained in sections 1.1 and 7.1 of this compilation.

Scientific typography

Section 1.3 explains the rules for writing scientific symbols and names, for example, where to use capital letters or italics, and where their use is incorrect. The typographical rules are extensive, including even such detail as whether "20°C" or "20 °C" is the correct form.

Atomic units

Section 3.8 introduces

atomic units The atomic units are a system of natural units of measurement that is especially convenient for calculations in atomic physics and related scientific fields, such as computational chemistry and atomic spectroscopy. They were originally suggested ...

and gives a table of atomic units of various physical quantities and the conversion factor to the

SI units The International System of Units, internationally known by the abbreviation SI (from French ), is the modern form of the metric system and the world's most widely used system of measurement. It is the only system of measurement with official st ...

. Section 7.3(v) gives a concise but clear tutorial on practical use of atomic units, in particular how to understand equations "written in atomic units".

External links

''Quantities, Units and Symbols in Physical Chemistry'', IUPAC ''Green Book'', third edition
( E.R. Cohen, T. Cvitas, J.G. Frey, B. Holmström, K. Kuchitsu, R. Marquardt, I. Mills, F. Pavese, M. Quack, J. Stohner, H.L. Strauss, M. Takami, and A.J. Thor, ''Quantities, Units and Symbols in Physical Chemistry'', IUPAC ''Green Book'', Third Edition, Second Printing, IUPAC & RSC Publishing, Cambridge (2008))
Concise four-page summary of the ''Green Book''{{'s third edition

Second edition of the ''Green Book''
Chemistry reference works Chemical nomenclature Units of chemical measurement IUPAP