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Significance of the Symbol of Elements

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An element in chemistry refers to the purest form of a substance containing only atoms and cannot be broken down further by any means. These elements are classified according to their properties (both chemical and physical) and arranged according to their atomic number (Z) in the modern periodic table. But before the introduction of chemistry and becoming an individual field from science, the scientists or the alchemist used series of arcane symbols to represent the chemical elements and compounds. Scientist John Dalton was the first to design his own set of symbols for elements and molecules. Later it was Berzelius who gave the method of the typographical method in which the elements were symbolized with letters of their name or their ancient names.

The general idea behind giving symbols to the elements was that even though these elements names were written differently in different languages these symbols played a common role in representing each of the chemical elements. Thus with the advancement of chemistry hundreds of the chemical elements had been discovered and today all those 118 elements have a unique symbol to represent them.

Elements and their Symbols

  • Every chemical element like Hydrogen, Helium, Oxygen or Carbon has unique letters to represent them called Symbols. For example, the element Hydrogen is symbolized with ‘H’, Helium with ‘He’, Oxygen with ‘O’ and Carbon with ‘C’.
  • The symbols have the first letter of their name in uppercase and the second letter in lowercase.
  • It is important to remember that no two elements have the same symbols to represent them. In few cases, the first letter in the symbol can be the same but the second letter can be never the same.  For example, Copper with the symbol ‘Cu’ and Chlorine with the symbol ‘Cl’ have the same first letter ‘C’ as the same but their second letter (‘u’ and ‘l’) is different which help to differentiate both the chemical elements.

Look at the following examples in the table for simple one-letter symbols.

Name of the element Symbol of the element

Hydrogen

H

Carbon

C

Nitrogen

N

Potassium

K

In the table given below look and try to differentiate the chemical elements as per their second letter in the symbol.

Name of the element

Symbol of the element

Carbon

C

Copper

Cu

Chlorine

Cl

Caesium

Cs

Cerium

Ce

Cobalt

Co

Chromium

Cr

In some cases, the chemical elements have symbols as per their ancient, Latin, Greek, Arabic or German names. Look at the interesting table below:

Name of the element  Latin name  Symbol

Latin

Sodium

Natrium 

Na

German

Gold

Aurum

Au

Iron

Ferrum

Fe

Copper

Cuprum

Cu

Arabic

Potassium

Kalium

K

 

General chemical symbols: 

When instead of referring to a particular chemical element,  the group of chemical elements is referred then they are represented with a set of general symbols not used for names of the specific chemical elements. For example,  the chemical elements present in group 17 of the periodic element called Halogens are represented by the symbol “X”.  To represent radicals ‘R” is used, “Q” represents heat in a chemical reaction, “E” and “N” represents the electrophile and nucleophile in an organic chemical reaction.

Significance of the Symbols

  • A symbol gives information on the stoichiometric quantity of the element. e.g. “B” represents one atom of the element Boron. Likewise, “S” and “Mg” represent one atom of Sulphur and one atom of Magnesium respectively.  As one atom is equal to 6.022 × 10-23 moles of particles. It can be interpreted that B has 6.022 × 10-23 moles of particles.
  • Atomic mass: In a balanced chemical reaction a particular symbol represents the definite mass of a particular element. Simply writing N means one atom of nitrogen which has an atomic mass of 14 u.
  • Compounds: In a complex reaction, it’s tedious to write the full chemical names of the compound. e.g. Consider the chemical reaction shown below. Is it easy to write Water (product formed) or simply H2O? With symbols right!
  • Identity: Every symbol is unique for every unique 118 elements. There should be no misunderstanding or misinterpretation while assigning or reading the chemical symbols. Ex- As explained above, “Ca, Cu, C, Cr, Cs, Cl” here even though they have the same first character, the second character is different. In sequence from left, they stand for Calcium, Copper, Carbon, Chromium, and Cesium.

Some Examples to understand:

Let’s look at the following chemical reactions to understand the concepts better.

Hydrogen + Oxygen ⇢ Water                                                                                                                                           ……… (a)

2H2 + 2O2 ⇢ 2H2O                                                                                                                                                            ……… (b)

Here both reactions a and b represent the same process of water formation. But, which way of writing the reaction is easier and more informative? Right! its b. Just looking at chemical reaction b, one could infer that hydrogen and oxygen (reactants) reacted under certain conditions to give water (product). What about the stoichiometric data? From reaction b, it can be also inferred that 2 moles of hydrogen molecules react with 2 moles of oxygen molecules to give 2 moles of water. 

Another important significance of the symbol of the element is that we can represent the elements with their respective Mass number (A) and Atomic number (Z) in a short way. For example, AXZ here X is the symbol of an imaginary element having mass number A and atomic number Z. Nitrogen has a mass number of 14 and atomic number 7 so it can be represented as “14N7“. The chemical compounds are also represented with symbols for easy identification. For example, look at the table below:

Name of the Compound Symbol

Water

H2O

Ammonia

NH3

Carbon dioxide

CO2

Methane

CH4

Every year, new chemical elements are found or invented by researchers. So, with little knowledge of the naming rules, we can easily symbolize them and they have the same meaning worldwide. Without these symbols classifying the elements in the IUPAC table would be a troublesome task. Try thinking of an IUPAC table with chemical element names and not symbols?

Sample Questions 

Question 1: What do you mean by the Symbol of elements in chemistry?

Answer: 

A symbol represents the name of a chemical element by using one or two-letter of the element name.

Question 2: Which is the correct notation for Chlorine “CL”, “cl” or “Cl”?

Answer: 

The first letter of the word should be capital and the second letter should be small, so neither “CL” nor “cl” is correct. The correct symbol for Chlorine is “Cl”.

Question 3: What are the symbols of Antimony, Tungsten, Silver, Mercury, Lead?

Answer:  

All these chemical elements are symbolized according to their Latin names: 

Name of the element Latin Name Symbol

Antimony

Stibium

Sb

Tungsten 

Wolfram

W

Silver 

Argentum

Ag

Mercury

Hydrargyrum

Hg

Lead 

Plumbum

Pb

Question 4: How will you represent the element Lithium with its atomic mass number(A) and atomic number(Z)?

Answer:  

Lithium has an atomic mass number (A) = 6.941 and atomic number (Z) = 3 . So it can be represented as ” 3Li6.941“.

Question 5: List all the elements whose name starts with S and write their symbols.

Answer:  

Here it can be observed that even though they all have “S” as their first letter in the chemical name their symbols are different.

Chemical names with S Symbols
Sulfur S
Scandium Sc
Strontium Sr
Selenium Se
Sodium Na
Silicon Si
Silver Ag
Seaborgium Sm
Samarium Sm


Last Updated : 17 Nov, 2022
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