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Weird Science: Chemical Symbols

NGSS Science and Engineering Practices

Chemists abbreviate the name of each element using a one or two-letter chemical symbol (SF Fig. 1.2). H is the abbreviation for hydrogen. Cl is the abbreviation for chlorine. The first letter of each symbol is capitalized and the second letter is lower case. The first letter of the symbol is usually the first letter of the element’s name.



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SF Fig. 1.2. Chemicals are represented by one- or two-letter symbols.

Image copyright and source

Image by Brittany Supnet


Chlorine and hydrogen have abbreviations that are easy to remember, but a few elements have symbols that do not seem to match their English names. Many of those symbols are taken from the Latin name of the element. For example, sodium has the symbol Na, which is taken from its Latin name natrium. Gold, Au, gets its name from the Latin word for gold, aurum. Other elements have symbols that come from their names in languages other than Latin or English. For example, tungsten, W, gets its symbol from its German name, wolfram. Potassium, K, comes from the Latin word kalium, which comes from the Arabic qali, which describes an ashy substance.


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SF Fig. 1.3.  Extent of the Roman Empire in AD 117. This is the area over which Latin would have been spoken.

Image copyright and source

Image courtesy of Ssolbergj, modified by Fan Yang


The Latin language was spoken in ancient Rome and was spread through Roman conquest. At it’s peak, the Roman Empire included most of Europe and large parts of the Middle East and Northern Africa (see SF Fig. 1.3 to see the extent of the Roman Empire in AD 117). Today, Latin is considered a dead language; only a few people can speak it fluently. However, Latin is still considered an important language to know because it is still with us in so many ways. Because of its geographical spread, Latin was used for a long time as a universal language of international communication, especially in the areas of science and law, and many of the words we still use in these fields come from Latin. Some of these have become so common that we no longer recognize them as Latin words. For example, the abbreviations a.m. and p.m. that we use in telling time stand for the Latin terms ante-meridian and post-meridian, which mean before mid-day and after mid-day. SF Table 1.2 shows some Latin terms that, while not used in everyday language, are standard terms in modern law and medicine.


SF Table 1.2. Common Latin phrases in law and medicine
Latin Phrase Translation Situation
ad litem for the lawsuit When a person is appointed by a court to act on another person's behalf.
de facto by the fact Something that is common practice, but is not necessarily mandated by law.
habeas corpus you are to have the body A legal action that requires a person under arrest to be brought before a judge or court, in order to prevent unlawful detention.
bona fide in good faith Acting with honest and good intentions in legal transations.
placebo I shall please A medical treatment that is not effective, but intended to trick a patient into believing it will work.
rigor mortis stiffness of death One of the recognizable signs of death, caused by chemical changes in muscles, which bcome stiff.
in situ in position In medicine, can refer to cells or organs that are located in the correct or expected position in the body.


Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.