Atomic symbol

An atom symbol is a symbol that consists of several overlapping ellipses that are oriented towards a common center point, which is usually also shown .

Derivation and design

The symbol is the stylized representation of an atom based on Bohr's atomic model developed in 1913 . This postulated that electrons orbit the atomic nucleus like planets orbit the sun. This model has shaped the popular image of atoms in the long run, although it has been scientifically overtaken by models that are less clear for non-experts since around 1925, in which electrons are only assigned certain probabilities of residence (see atomic orbital ).

The symbol usually consists of three, often four, sometimes two or more than four orbits around a central point, which are intended to be circular or sometimes also elliptical in three-dimensional space and are thus designed as ellipses in perspective in the two-dimensional symbol. The fact that the two electrons of the innermost shell ( K shell ) would have to have significantly smaller orbits in Bohr's atomic model is not taken into account in the symbol shape. The angles between the main axes of the ellipses are chosen according to aesthetic criteria without reference to physical atomic properties; they are often the same size throughout. One or two small balls are often shown on each of the tracks, which are supposed to symbolize the circling electrons. A sphere is often shown in the central point, symbolizing the atomic nucleus. When expanding to more complex symbols, another symbol can appear in the center, for example the cadaver in the logo of Ulm University .

Special stamp 1955 "German research funding"
Flag of the International Atomic Energy Agency (IAEA)
Logo of Ulm University (excerpt)
Coat of arms of Gundremmingen
Facade of a nuclear power plant near St. Petersburg , Russia
Uranium Mining Memorial in Elliot Lake , Ontario, Canada

meaning

In addition to atoms, the sign can also symbolize nuclear physics and nuclear energy . It can be used as a map sign for nuclear power plants . Occasionally it symbolizes exact science in general . As an iconic representation of the atom, it can be found in logos (e.g. the IAEA ), in coats of arms (see atomic symbol (heraldry) ), in caricatures and in popular science illustrations.

⚛️

Emoji

Characters and Emoji

The symbol has been in Unicode since version 4.1 (March 2005) as the character U + 269B ⚛ atom symbol in the Unicode block Various symbols and is now also standardized as an emoji .

Atom symbol in the Segoe UI Symbol, DejaVu Sans, and Symbola fonts

Web links

Commons : Atoms in Art - Collection of Images, Videos and Audio Files

Individual evidence

↑ ^a ^b Carl G. Liungman: symbol. Encyclopedia of Western Signs and Ideograms. 1995 (reprint 2003), ISBN 91-972705-0-4 , page 226
↑ Example: Iran-Winter-Games.htm ( memento from October 10, 2012 in the Internet Archive ), a 2010 cartoon on Iran's nuclear policy .
↑ Example: First direct observation of atoms in gas. scinexx .de, September 19, 2016, accessed on September 19, 2016 . The cover illustration was made available to the press by MIT .
↑ Michael Everson : Unicode Document L2 / 03-163R2: Proposal to encode five miscellaneous symbols in the UCS. Unicode Technical Committee, September 4, 2003, accessed September 7, 2018 .

[Liungman-1] Carl G. Liungman: symbol. Encyclopedia of Western Signs and Ideograms. 1995 (reprint 2003), ISBN 91-972705-0-4 , page 226

[2] Example: Iran-Winter-Games.htm ( memento from October 10, 2012 in the Internet Archive ), a 2010 cartoon on Iran's nuclear policy .

[3] Example: First direct observation of atoms in gas. scinexx .de, September 19, 2016, accessed on September 19, 2016 . The cover illustration was made available to the press by MIT .

[4] Michael Everson : Unicode Document L2 / 03-163R2: Proposal to encode five miscellaneous symbols in the UCS. Unicode Technical Committee, September 4, 2003, accessed September 7, 2018 .