Theory:

A symbol is an image or object, etc. that refers to something.

For example, mathematical operators \(+\) and \(-\) denote addition and subtraction, respectively. In the same manner, in chemistry, each element is denoted by a symbol.
 
History of symbols:
  
Ancient people have used the below-listed symbols.
  • Greek symbols
  • Alchemist symbol
  • Dalton symbols
  • Pictorial symbols
  • Berzelius symbols
Greek symbols:
 
The symbols were in the form of a geometrical shape. Ancient Greek people have used these symbols.

These symbols represent the four basic elements around us: air, Earth, fire and water.
 
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Alchemist symbol:
  
During the days of the alchemist, the different materials that they used were represented by Greek symbols. They tried to change less valuable metal into gold. This process was called alchemy, and the men who did the process were known as Alchemists.

Alchemy symbols sometimes have hints to the properties of the element as well as the history of the element.
 
Dalton symbols:
 
In 1808, John Dalton, an English scientist, tried to name the various elements based on the pictorial symbols. Since these symbols are difficult to draw, they were not used.
 
3.png
 
Daltons 1808AD(CE) symbols and formulae:
 
1.png
Dalton symbols
 
Berzelius symbols:
 
In 1813, Jon Jakob Berzelius came up with a system using letters of the alphabet rather than signs. The modified version of Berzelius system follows under the heading 'System for Determining Symbols of the Elements'.
Reference:
file:///C:/Users/user/Desktop/Books/8th_Science/TN/8th_Std_Term_I_Science_EM.pdf