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Chemical symbols

A chemical symbol    is an abbreviation that we use to indicate an element or an atom of an element. For example, the symbol for mercury is Hg ( [link] ). We use the same symbol to indicate one atom of mercury (microscopic domain) or to label a container of many atoms of the element mercury (macroscopic domain).

A jar labeled “H g” is shown with a small amount of liquid mercury in it.
The symbol Hg represents the element mercury regardless of the amount; it could represent one atom of mercury or a large amount of mercury.

The symbols for several common elements and their atoms are listed in [link] . Some symbols are derived from the common name of the element; others are abbreviations of the name in another language. Most symbols have one or two letters, but three-letter symbols have been used to describe some elements that have atomic numbers greater than 112. To avoid confusion with other notations, only the first letter of a symbol is capitalized. For example, Co is the symbol for the element cobalt, but CO is the notation for the compound carbon monoxide, which contains atoms of the elements carbon (C) and oxygen (O). All known elements and their symbols are in the periodic table in [link] (also found in [link] ).

Some Common Elements and Their Symbols
Element Symbol Element Symbol
aluminum Al iron Fe (from ferrum )
bromine Br lead Pb (from plumbum )
calcium Ca magnesium Mg
carbon C mercury Hg (from hydrargyrum )
chlorine Cl nitrogen N
chromium Cr oxygen O
cobalt Co potassium K (from kalium )
copper Cu (from cuprum ) silicon Si
fluorine F silver Ag (from argentum )
gold Au (from aurum ) sodium Na (from natrium )
helium He sulfur S
hydrogen H tin Sn (from stannum )
iodine I zinc Zn

Traditionally, the discoverer (or discoverers) of a new element names the element. However, until the name is recognized by the International Union of Pure and Applied Chemistry (IUPAC), the recommended name of the new element is based on the Latin word(s) for its atomic number. For example, element 106 was called unnilhexium (Unh), element 107 was called unnilseptium (Uns), and element 108 was called unniloctium (Uno) for several years. These elements are now named after scientists (or occasionally locations); for example, element 106 is now known as seaborgium (Sg) in honor of Glenn Seaborg, a Nobel Prize winner who was active in the discovery of several heavy elements.


The symbol for a specific isotope of any element is written by placing the mass number as a superscript to the left of the element symbol ( [link] ). The atomic number is sometimes written as a subscript preceding the symbol, but since this number defines the element’s identity, as does its symbol, it is often omitted. For example, magnesium exists as a mixture of three isotopes, each with an atomic number of 12 and with mass numbers of 24, 25, and 26, respectively. These isotopes can be identified as 24 Mg, 25 Mg, and 26 Mg. These isotope symbols are read as “element, mass number” and can be symbolized consistent with this reading. For instance, 24 Mg is read as “magnesium 24,” and can be written as “magnesium-24” or “Mg-24.” 25 Mg is read as “magnesium 25,” and can be written as “magnesium-25” or “Mg-25.” All magnesium atoms have 12 protons in their nucleus. They differ only because a 24 Mg atom has 12 neutrons in its nucleus, a 25 Mg atom has 13 neutrons, and a 26 Mg has 14 neutrons.

Questions & Answers

what is coordination number
coordination number is the number of atoms or ions immediately surrounding a central atom in a complex or crystal
what is isotope
who is the father of chemistry
Roland Reply
Antoine Lavoisier. Father of modern chemistry
What is geometric isomerism
Imoh Reply
pls I don't really know teach me
geometric isomerism are molecules that are locked into their spatial position with respect to one another due to a double Bond or ring structure
Chromatography is a physical method of seperation where by mixtures that are in two phrases are separated
Lexzzy Reply
What is chromatography?
Chukwudi Reply
meaning of electrode
is ion exchange and ion chromatography the same process?
define boyes law and give the formula
Esther Reply
define chemistry and it's properties
Boyle's law state that at a constant temperature, the pressure of a fixed mass of gas is inversely proportionally to it's volume. P=k/v P1v1=p2v2
Chemistry is the study of matter and it's properties..... It's deals with the composition that governors d use of matter..... Chemistry is also d study of chemical reaction of a substance and it's matter. Properties of chemistry Atom Elements Compound Molecules
chemistry seems more accurately defined as the measurement and study of the interaction / behavior that occurs between any given person place or thing or unit of measure, ie time and energy correlation
Reactive metals are extracted by _______?
Joseph Reply
electrolytic reduction
what is ionxide
Wisdom Reply
What is isometrics
Kamaluddeen Reply
Molar mass of aluminum
Victor Reply
why an equation should balanced?
Kwanele Reply
in order to obey the law of conservation of mass
why does the atomic radius increase across the period
Timothy Reply
preparation of hydrogen in the laboratory
Emmanuel Reply
state the dual nature of an electron
Celine Reply
no you PunOko

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Source:  OpenStax, Chemistry. OpenStax CNX. May 20, 2015 Download for free at http://legacy.cnx.org/content/col11760/1.9
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